Can You Get Pregnant on Birth Control

In this article, we look at how effective the birth control pill is and give five reasons why the pill might fail. We also provide tips on how to prevent pill failure and describe some early signs of pregnancy.

Can You Get Pregnant on the Pill?

Yes. Although birth control pills have a high success rate, they can fail and you can get pregnant while on the pill. Certain factors increase your risk of getting pregnant, even if you’re on birth control. Keep these factors in mind if you’re sexually active and want to prevent an unplanned pregnancy.

Birth control pills are 99 percent effective with “perfect use,” which means taking the pill at the same time every day without missing a dose. “Typical use” is how most women take the pill, and then it’s about 91 percent effective. Both combined oral contraceptives and progestin-only pills (also known as the mini pill) have a typical failure rate of 9 percent.

Many women accidentally miss a dose or forget to start a new pack of pills. When that happens, the chances for an accidental pregnancy go up.

Certain conditions or behaviors can increase the likelihood that your birth control won’t be as effective at preventing pregnancy.

If you can’t remember to take your pill at the same time every day, you increase your risk of pregnancy. Birth control pills are designed to maintain a constant level of hormones in your body. If you skip or miss a dose, you hormone levels can drop quickly. Depending on where you are in your cycle, this may cause you to ovulate. Ovulation can increase your chances of becoming pregnant.

The problem isn’t a shortage of people wanting to be doctors, but rather, too few opportunities for training. Medical schools have increased class sizes by 30% since 2002, but federal funding for residency training – an essential step in the process of becoming a practicing physician – has not increased since 1997, according to Inside Higher Ed.

Reckless alcohol consumption can also cause birth control failure. While under the influence, some women may forget to take their pill at the correct time. If you vomit too soon after taking your pill, your body may not be able to absorb any of the hormones. This can result in a drop in your hormone levels, which could trigger ovulation.

Taking another medication or supplement at the same time as your birth control pill can also affect the pill’s effectiveness.

Keep these tips in mind if you’re on birth control and want to prevent pregnancy.

Time it right

Make sure you take your birth control pill at the same time every day. Set a reminder on your phone or watch if you need to. You may also consider taking the pill with a specific daily activity, such as during lunch or dinner.

If you take progestin-only pills, you should be especially careful about taking the pill at the same time every day. If you’re late with a dose or skip one altogether, your hormone levels can drop very quickly. This could cause you to ovulate and that greatly increases your chances for getting pregnant.

If you miss a dose, use a backup method or avoid sex for the next week. To be extra cautious, use a backup method, such as a condom, or avoid sex for the next month.

Take the placebo pills

Combination pill packs typically contain three weeks of active pills that contain hormones and one week of inactive, or placebo, pills. Although it isn’t medically necessary to take the placebo pills, doing so can help you stay in your routine.

If you choose to skip the placebo pills, there’s a chance that you may be late in starting your next pill pack. This can interrupt your body’s expected level of hormones and cause you to ovulate. Ovulation increases your chances of being pregnant.

Don’t mix medications

Some prescription and over-the-counter medications may interfere with your birth control’s effectiveness. Before you begin taking a new medicine, ask your doctor or pharmacist if you should use a backup method of protection while taking this new medication.

Although some antibiotics have been anecdotally connected to unplanned pregnancies, research has largely debunked this connection. A possible connection with reduced birth control effectiveness is only recognized with one type of uncommon antibiotic called rifampin.

Don’t use St. John’s wort

St. John’s wort is a popular over-the-counter herbal supplement that can affect liver metabolism. This supplement can interfere with birth control’s effectiveness. You could experience breakthrough bleeding and possibly an unplanned pregnancy if you take the two medicines together. Talk with your doctor about any additional measures you should take, including a backup protection method while you’re taking St. John’s wort.

Knowing what can make your birth control ineffective and how you can increase your chances for successfully avoiding pregnancy will help you make the best decisions for yourself.

The earliest symptoms of pregnancy can be easily overlooked, especially if you’re on birth control. If you experience any of these symptoms, take a pregnancy test to confirm your pregnancy status. If you want to double check the at-home pregnancy test, a simple blood test by your doctor can confirm your status.

The early signs of pregnancy include:

• tender or swollen breasts (hormonal changes can affect the way your breasts feel)
• a sudden aversion to certain foods or scents
• unusual food cravings

Morning sickness

Nausea, vomiting, and fatigue are also signs of early pregnancy. Contrary to its name, morning sickness can occur at any time of the day. It can begin very early after conception. While your body adjusts to the new pregnancy, you may also find yourself growing tired more easily or more quickly.

Missed period

Many women begin suspecting they’re pregnant when they miss a period. Unfortunately, some women don’t have a period while on birth control, so a missed period may not necessarily be an easy indicator.

Implementation bleeding, which happens when a fertilized egg attaches to your uterus, can be mistaken for a period. This is especially true if your period is typically very light.

Can You Get Pregnant on Birth Control?

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Latest update:

Medically reviewed to ensure accuracy.

Wondering if it’s possible to get pregnant on the pill or another form of hormonal birth control? Here’s what you need to know about birth control effectiveness, plus how to prevent it from failing if you’re trying to avoid pregnancy.

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In This Article

• Can you get pregnant on the pill?
• Can you get pregnant if you have an IUD?
• Can you get pregnant if you have an implant?
• Can you get pregnant if you have had the Depo-Provera shot?
• Can you get pregnant on the patch?
• Can you get pregnant if you use spermicide?
• Can you get pregnant if you use vaginal contraception?
• Can you get pregnant if you use condoms?
• Can you get pregnant if you have had a bilateral tubal ligation?
• How to prevent your birth control from failing

Nearly all women use some form of birth control during their lifetime, and almost two-thirds are currently using it at any point in time. But while there are many different types of birth control available, the effectiveness of each type can vary dramatically, ranging from more than 99 percent for the birth control implant Nexplanon to only about 72 percent for spermicide. Trusted Source Centers for Disease Control and Prevention Effectiveness of Family Planning Methods See All Sources [1]

If you’re not currently trying to get pregnant, here’s what you need to know about the effectiveness of some of the most common types of birth control.

Can you get pregnant on the pill?

Oral contraceptives — a pill taken daily that contains two hormones, estrogen and progesterone — are 99.7 percent effective with perfect use. This means that fewer than one out of 100 women who take the pill become pregnant in a year.

But with typical use, the effectiveness of the pill drops down to 91 percent. There are a few reasons for this: If you forget and skip a day, especially with one of the newer, lower-dose pills, your hormone levels may not remain at consistent enough levels to prevent you from getting pregnant. One type of pill, the progestin-only pill known as the mini-pill (commonly used among breastfeeding moms), needs to be taken within the same three-hour window every day to remain effective. Trusted Source American College of Obstetricians and Gynecologists Postpartum Birth Control See All Sources [2]

While it’s rare for medications to interfere with the pill, the antibiotic rifampin, the antifungal drug griseofulvin, the herb St. John’s Wort and some epilepsy drugs and antiviral medications can make the pill less effective. The pill has also been shown to be less effective in women who are overweight or obese, in which case your doctor may recommend a higher-dose option. Trusted Source National Institutes of Health Obese Women Need Higher or Continuous Dose for Oral Contraceptive Success See All Sources [3]

Read This Next

Can you get pregnant if you have an IUD?

Intrauterine devices (IUDs) are one of the best birth control methods out there as they’re 99 percent effective. These small pieces of T-shaped plastic — about the size of a quarter — are placed inside your uterus to prevent pregnancy.

In the rare event an IUD fails, it’s usually because it falls out of place (something called IUD expulsion). This sometimes causes symptoms like heavy bleeding, cramping or vaginal discharge.

Can you get pregnant if you have an implant?

The birth control implant (known by the brand name Nexplanon) is a flexible plastic rod about the size of a matchstick that is placed under the skin of your upper arm. It releases a low, steady dose of synthetic progestin to thicken your cervical mucus and thin the lining of the uterus, preventing pregnancy.

Nexplanon is actually the most effective birth control option out there, with a failure rate of only .05 percent. That means that out of 10,000 women, only five using the implant will get pregnant within a year. This is almost always due to incorrect insertion rather than the implant itself.

Can you get pregnant if you have had the Depo-Provera shot?

The most common reason for pregnancy with Depo-Provera — a shot that contains the hormone progestin — is not getting it on time (every 12 to 13 weeks). If you do stay on top of it, the pregnancy rate after one year of use is very low. But with typical use, the failure rate hovers around 6 percent. If you think it will be hard to keep up with your shots, you should look for another method of birth control.

Can you get pregnant on the patch?

The birth control patch, like the birth control pill, contains synthetic estrogen and progesterone that “fools” your body into thinking it’s pregnant. You wear the patch on your belly, upper arm, butt or back, and your skin absorbs the hormones into your body.

The patch has a similar rate of effectiveness to the birth control pill — around 9 percent. The main reason women get pregnant on the patch is because they forget to take it off and replace it once a week. With “perfect” use, however, the effectiveness rate is around 99 percent.

Can you get pregnant if you use spermicide?

If you’re just using spermicide — a chemical that you put deep within the vagina before you have sex — alone, it’s not a reliable method of birth control. More than a quarter of all women — 28 percent — will get pregnant using just this method.

Spermicide helps prevent pregnancy by blocking the entrance to the cervix so sperm can’t get to the egg, as well as slowing sperm down. It’s great to use in addition to other birth control methods such as condoms, diaphragms or cervical caps, but not reliable enough to use by itself.

Can you get pregnant if you use vaginal contraception?

Contraception that you insert into your vagina — such as a diaphragm cervical cap or sponge — is not as effective as hormonal methods. For most women, vaginal contraception offers around an 88 percent chance at preventing pregnancy. The main reason why these forms of birth control fail is because they weren’t inserted correctly, or if you don’t use them every time you have sex.

If you want to boost their effectiveness, use a spermicide. And if you’ve had at least one baby, think twice about using the sponge. In these cases, it only has an effectiveness rate of about 75 percent. (However, diaphragms and cervical caps are both re-fitted after you give birth, which makes it much less of an issue.) If you do choose to use a sponge after giving birth, you should wait at least six weeks.

Can you get pregnant if you use condoms?

If you use condoms perfectly every single time you have sex, they’re 98 percent effective at preventing pregnancy. But most people don’t use them perfectly, so in real life, condoms are about 85 percent effective. That means almost one in five women will get pregnant each year if they just use condoms.

The best way to make sure condoms are as effective as possible is to use them correctly. Some of the most common mistakes include:

• Putting them on too late, or pulling them off too early
• Not leaving space at the tip of the condom for semen
• Not checking for damage before use
• Using an oil based-lubricant like Vaseline or massage oil, which can damage the latex

Can you get pregnant if you have had a bilateral tubal ligation?

The chances of getting pregnant naturally after a tubal ligation, where the fallopian tubes are cut, tied or blocked to permanently prevent pregnancy, are very low, just 0.5 percent. That means only about one of every 200 women who have this surgery get pregnant each year.

How to prevent your birth control from failing

The best way to make sure your birth control works is to pick the method that’s right for you. For example, if you don’t think you’ll be able to remember to take a pill every day, you’d be better off using a semi-permanent option, such as an IUD or implant. These also are the most effective options.

On the other hand, if you’re squeamish about hormones or need to avoid them because you have a chronic health condition such as high blood pressure, a barrier option such as condoms or a diaphragm would be a better choice. Just keep in mind that since barrier methods are less effective than an IUD or a hormonal method, if you’re actively trying to avoid pregnancy, you may want to consider doubling up — with, say, condoms and spermicide — for extra assurance.

Sources

References

1. Centers for Disease Control and Prevention, Effectiveness of Family Planning Methods, 2014. | Show in the article
2. American College of Obstetricians and Gynecologists, Postpartum Birth Control, November 2021. | Show in the article
3. National Institutes of Health, Eunice Kennedy Shriver Institute of Child Health and Human Development, Obese Women Need Higher or Continuous Dose for Oral Contraceptive Success, January 2015. | Show in the article
4. WhatToExpect.com, What Birth Control Should You Use After Pregnancy?, March 2022.
5. WhatToExpect.com, IUDs as Birth Control: What New Moms Need to Know, April 2022.
6. Andrei Rebarber, M.D., Co-Director of the Division of Maternal Fetal Medicine at Englewood Hospital Medical Center, New York, NY, and Member of the What to Expect Medical Review Board.
7. Sarah Obican, M.D., Assistant Professor in the Department of Obstetrics and Gynecology at the Morsani College of Medicine at the University of South Florida, Tampa, FL, and Member of the What to Expect Medical Review Board.
8. American College of Obstetricians and Gynecologists, Long-Acting Reversible Contraception: Implants and Intrauterine Devices, 2021.
9. Sexual Health, Condom Use Errors and Problems: A Global View, February 2012.

Updates history

September 15, 2022

Editor: Caroline Picard

• Minor copy and formatting changes.
• Medically reviewed to ensure accuracy.

Can a person get pregnant while taking the pill?

Birth control pills are a popular and effective way to prevent pregnancy. However, missing pill days, vomiting, and certain medications, among other factors, can reduce its effectiveness. This could lead to an unintended pregnancy.

Anyone who is worried that they might not be able to take the pill correctly should discuss other birth control options with a healthcare professional.

In this article, we look at how effective the birth control pill is and give five reasons why the pill might fail. We also provide tips on how to prevent pill failure and describe some early signs of pregnancy.

The combined pill contains hormones that prevent ovulation, which is when the ovaries release an egg for fertilization. Another type of pill, known as the minipill, causes a person’s cervical mucus to thicken and the uterine lining to thin, which reduces the likelihood of sperm reaching an egg.

The birth control pill is very effective if a person takes it correctly and does not miss any pill days. According to the Centers for Disease Control and Prevention (CDC), the pill is 99.7% effective with perfect use. This means that fewer than 1 in 100 people who take the pill may become pregnant in 1 year.

However, with typical use, the effectiveness of the pill is 91%, meaning that about 9 in 100 people may become pregnant in a year of taking it.

How does the pill compare with other birth control methods?

There are different types of birth control methods, some of which are hormone-based and some of which are not. The effectiveness of each type also varies according to the limitations of typical use. Certain types of birth control may be a better fit for a person than others.

In addition to the combination birth control pill, other contraceptive methods include:

• progestin-only minipill
• birth control patch
• birth control shot
• vaginal ring
• emergency morning-after pill
• intrauterine device (IUD)
• tubal ligation
• female condom
• sponge
• diaphragm
• cervical cap
• fertility awareness, or natural birth control methods

In addition, there are a few male contraceptive options, but these are much more limited. They include condoms, vasectomy, and the withdrawal method, which is not particularly reliable. Researchers are currently investigating a male birth control pill in clinical trials.

Although the birth control pill generally works very well, some situations can reduce its effectiveness, and they may sometimes result in an unintended pregnancy. These include:

Missing a day

Manufacturers intend for people to take the pill daily. If a person misses a day, their hormone levels may not remain at consistent enough levels to prevent pregnancy.

If a person finds it difficult to take the pill on a daily basis, other birth control methods may better suit their needs. A doctor or gynecologist can advise on the range of alternative contraceptives.

Vomiting or severe diarrhea

Sometimes a person may be ill when they take the pill. When a person vomits, the pill can come back up, or they may not fully absorb it into their body. The latter may also occur if a person has severe diarrhea.

Anyone who experiences vomiting or diarrhea shortly after taking the pill should take another pill as soon as possible and then take their next pill as usual.

Not taking the pills at the same time each day

In addition to taking birth control pills daily, a person should take the pills at about the same time each day. Doing so can maintain their hormone levels more consistently.

A person should always take the minipill within the same 3-hour time window every day. Someone who misses their usual window should use a backup birth control method for the next 7 days or avoid having sex.

Many people set a daily alarm reminding them to take their pill at the correct time each day.

Not starting a new pack right away

It is essential to start a new pack of pills the day after finishing the previous one. However, a person may not always have their new pack in time. Missing a few days between packs can make the pill less effective in preventing pregnancy.

According to the CDC, anyone who misses two or more pills in a row should use a backup birth control method or avoid sexual intercourse until they have taken the birth control pill for 7 consecutive days .

Medications that interfere with the pill

Some medications can make the pill less effective. These medications include certain antibiotics, such as rifampicin, and antifungal drugs, such as griseofulvin.

A person should use backup contraception while taking these medications and for 48 hours after finishing the course.

Other long-term medications and supplements may also affect how well birth control pills work. These include:

• epilepsy drugs, such as phenobarbital, phenytoin, and carbamazepine
• antiviral medications for the treatment of HIV
• St. John’s Wort, which is a herbal remedy