Overview

Birth control methods have high rates of effectiveness if they are used consistently. Follow your health professional's instructions on what to do if you miss or skip your birth control pills. Some general guidelines are listed here.

Combination (estrogen plus progestin) birth control pills

Always read the pill label for specific instructions. Or call your doctor. How likely pregnancy is depends on a few things, such as when you missed the pill, how many pills you missed, what kind of pills you take, and whether you had sex.

Here are some basic guidelines:¹

• If you miss one hormone pill, take it as soon as you remember. You may need to use a backup birth control method.
• If you miss two or more hormone pills, take 1 pill as soon as you remember you forgot them. Then read the pill label or call your doctor about instructions on how to take your missed pills. Pregnancy is more likely. So use a backup method of birth control for 7 days.
• If you miss pills and have had sex without a backup method of birth control, you can use emergency contraception, such as Plan B. You can use emergency contraception for up to 5 days after having had sex, but it works best if you take it right away.

Emergency contraception

If you had unprotected sex during the time that you missed taking pills, you can use emergency contraception to help prevent pregnancy. You can buy the emergency contraceptive Plan B (sometimes called the "morning-after pill") in most drugstores.

• If you are 17 or older, you can get Plan B from a pharmacist, without a prescription. Bring proof of your age.
• If you are younger than 17, you can get Plan B with a prescription from a doctor.

Illness

Vomiting and diarrhea can decrease the effectiveness of birth control pills. It is recommended that another method of birth control be used for 7 days after you have had the flu, even if you did not miss any pills.

Talk to your doctor if you are taking medicines for epilepsy (phenytoin and barbiturates) or tuberculosis (rifampin). These medicines may interfere with how well your birth control pills work.

Progestin-only pills

Progestin-only pills must be taken at the same time each day. If you take a pill more than 3 hours late, take it as soon as you remember even if that means you will take 2 pills in one day. Use another method of birth control for the next 48 hours to prevent pregnancy.² Consider using emergency contraception if you have had sex in the past 3 to 5 days.