Can You Get Pregnant on the Pill?

Getting Pregnant While on the Pill. It's Possible!

Just because you're on birth control pills, that doesn't mean that you can't get pregnant. The truth is, the only birth control method that is 100 percent effective at preventing pregnancy is abstinence. Yet when taken correctly, birth control pills are very effective at preventing pregnancy. Here's how birth control pills prevent pregnancy, the ways you can still get pregnant while on them, and what to do if the pregnancy test does give a positive result.

How Birth Control Pills Prevent Pregnancy

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Birth control pills prevent ovulation. Ovulation is when an egg is released from the ovary and pushed down the fallopian tube to the uterus, where it then waits to be fertilized by a sperm. Besides preventing ovulation, birth control pills prevent pregnancy by thickening the mucus in the cervix, which makes it harder for sperm to reach and fertilize the egg.

The Effectiveness of Birth Control Pills

When taken correctly, birth control pills are 99 percent effective at preventing pregnancy. This means than even when taken correctly, there is still that 1 percent chance that you may get pregnant while on the pill.

There are two types of birth control pills: combination pills and progestin-only pills, also known as mini-pills. Both combination and progestin-only pills require a doctor's prescription to get and renew. Combination pills contain the hormones estrogen and progestin. As the name implies, progestin-only pills contain only progestin. Combination pills come in 28-day, 21-day and 91-day packs. Progestin-only pills come in 28-day packs. With the exception of combination 21-day pill packs, birth control packs have both pills that contain hormones, sometimes called "active" pills, and placebo pills, sometimes called "inactive" pills. Placebo pills are included mainly to help you remember to take a pill a day.

For combination pills, it's not required that you take a pill at exactly the same time every day so long as you take one a day. The exception is if you're using 21-day packs, then you'll take one pill a day for three weeks and not take any pills for the fourth week before beginning a new pack.

Progestin-pills are different. In order for progestin-only pills to be effective, you not only have to take one every day, you have to take them within the same three hours every day. That means that if you take one pill at 2:00 p.m. today, you'll need to take the next one before 5:00 p.m. tomorrow, or else you increase your chances of getting pregnant.

When Birth Control Pills Start Working

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When birth control pills start working to prevent pregnancy depends on the type of birth control pill you're on. Combination pills start working right away if you start taking them within five days of the start of your period. If you start taking them at any other time, you'll be protected from pregnancy after a week (seven days). For example, if you get your period Tuesday morning, you can start taking combination pills anytime until Sunday morning and you'll be immediately protected from pregnancy. If you wait until after Saturday morning to start taking your combination pills, you won't be protected against pregnancy until after a week of taking them. For progestin-only pills, you can start them at any time and they will start working after two days (48 hours).

Getting Pregnant on the Pill

As stated before, there's still a very small chance that you'll get pregnant, even when you take your birth control pills according to the directions. The chances of getting pregnant increases when you miss pills. When you get a pill pack, it'll contain instructions on how to take the pills and what to do if you miss a pill or more.

For example, the instructions for the birth control brand Ortho Tri-Cyclen Lo says that if you miss one "active" pill one day, then you should take it as soon as you remember and then take your next pill at your regular time. If you miss two or more "active" pills, not only will you need to follow the instructions on how to proceed with the pills, but you will also need to use a backup method of birth control.

Other things that can lower the pill's effectiveness is if you have an illness that causes you to vomit or have diarrhea for more than 48 hours. Taking certain medications and supplements, such as the antibiotic Rifampin, the herb St. John’s Wort and certain HIV medicines, can also lessen the pill's effectiveness. Very overweight women may also be less protected against pregnancy while on the pill.

Due to the factors above and because some people don't take birth control pills as directed, about nine out of 100 women on the pill do get pregnant each year.

Tips for Using Birth Control Pills

It can be easy to forget to take a birth control pill every day. If you're using progestin-only pills, it can be especially hard to remember to take a pill within the same three hours every day. One way to help be consistent is to choose a time when it's usually convenient for you to take medication and set an alarm on your phone or clock to ring at that designated time. If you have a very consistent routine to your days, you may decide to take your pills after a certain event, such as when you wake up, eat lunch or prior to bedtime. If you're frequently out of the house and/or have an unpredictable schedule, consider keeping your pack of pills in your purse.

Other Forms of Birth Control

Remember that even when you take birth control pills correctly, there is still a one percent chance that you'll get pregnant. While on the pill, you may want to consider using a backup birth control method such as condoms, cervical caps and diaphragms. It is especially important to use a backup birth control method when you forgot to take a pill or just started using birth control pills and are still in the waiting period.

If you think that it'll be hard for you to remember to take a pill every day around the same time, consider another form of birth control, such as the birth control implant, shot or intrauterine device (IUD). Not only do these birth control methods not require that you take a pill every day, they are more effective at preventing pregnancy than birth control pills. The birth control implant, for example, is 99 percent effective at preventing pregnancy for four years after it's inserted into your arm by a doctor. The birth control shot, which is 94 percent effective, is administered by a doctor or nurse about every three months. The IUD, which is a small piece of flexible plastic that's inserted into your uterus by a doctor, is 99 percent effective and prevents pregnancy from three years up to 12 years, depending on the type and brand of IUD.

Pregnancy Symptoms

Since there's still a chance that you can get pregnant while on the pill, it's important to recognize pregnancy symptoms and get medical care if you are. Pregnancy symptoms differ from woman to woman and pregnancy to pregnancy. Common symptoms include a missed period, nausea, swollen or tender breasts and fatigue. Other symptoms include backaches, headaches, frequent urination, food cravings or aversions, darkening of the areolas and mood swings. Some women experience pregnancy symptoms as early as a week after conception while others don't experience any symptoms until they miss a period. If you think that you might be pregnant, take a home pregnancy test. If the pregnancy test turns out positive, stop taking birth control pills and make an appointment with your doctor.

Getting Pregnant Off the Pill

If you're on the pill but decide you want to get pregnant, simply stop taking the pills. While it may take a few months for your menstrual cycle to go back to nomral, you can still get pregnant right after you stop them.

Talk to Your Doctor About the Pill

If you're interested in taking birth control pills, talk to your doctor to discuss whether you're a good candidate for them, the benefits and advantages and which brand of birth control might be the right fit for you. Birth control pills aren't recommended for women who smoke and are over the age of 35 because of the risk of cardiovascular disease. If you have high blood pressure, your doctor may also advise against taking birth control pills because it may slightly increase your blood pressure.

Besides helping to prevent pregnancy, other benefits of birth control pills include reducing acne and making periods regular and easier. Yet some women also experience side effects such as lowered sexual desire, nausea and headaches. There are many brands of birth control out there, and some women do better on one than another. If you start taking birth control pills and experience negative side effects, talk to your doctor about switching to another brand. Also talk to your doctor if you find that taking birth control pills are too hard for you and you want to try another birth control method, such as the IUD.