Can You Get Pregnant on Birth Control Pills?

Birth control pills can cause an assortment of pregnancy-like symptoms, such as nausea, breast tenderness and missed periods. This is likely to leave you wondering if you could possibly be pregnant despite the fact that you are taking the pill. While pregnancy is possible if you are on birth control pills, it is not likely.

Failure Rate

Aside from abstinence, every birth control method has at least a small rate of failure. The pill is no exception to this rule. According to Planned Parenthood, if you were to take the pill every single day exactly as directed, you would run a 1 in 100 chance of becoming pregnant in any given year. Planned Parenthood also reports that typical use leaves as many as 8 in 100 women pregnant each year.

Dosage

Many prescription drugs come in varying doses. This allows doctors to prescribe medicines based on the patient’s size. Birth control pills come in a one-size-fits-all format. This leaves larger women running a greater risk of becoming pregnant since the hormones are more diluted in a larger body, according to the National Women’s Health Information Center website. If you are taller or heavier than average, you may want to ask your physician about your options.

Drug Interactions

Several drugs and supplements are known to reduce the effectiveness of birth control pills, according to the Pregnancy website. The most commonly known culprit is the antibiotic. Other prescription drugs, like some anti-seizure and HIV drugs, may also reduce effectiveness. Before taking any prescription drugs, discuss with your doctor the potential for a drug interaction. However, prescription drugs are not the only concern. Some herbal supplements may also cause you to become pregnant, like St. John’s wort, for instance.

Illness

If you have recently been sick with vomiting or diarrhea, you may need to utilize another form of birth control, due to diminished absorption of the pill. The Pregnancy website also warns that being sick can compromise your immune system, altering the way your body absorbs the pill. Any illness should be taken as a serious potential for getting pregnant on birth control pills.

Timing

Many women take several different birth control pills over their lifetimes. While every pill is similar in the way that it must be taken daily, progesterone-only pills must be taken at the same time each day to maintain the right level of hormones. If you are used to taking a combination pill that does not require such precise timing and have switched to a progesterone-only pill, you will want to be aware of this important difference.

Missed Pills

You have undoubtedly missed a pill or two without any problems in the past. However, if you miss more than two pills in a cycle, you do run a higher risk of becoming pregnant on birth control pills. If you have missed multiple pills in a cycle, the Pregnancy website suggests using another form of birth control until your next cycle begins.