What to do about missed or skipped birth control pills

From Healthwise

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

The greatest risk for pregnancy occurs if you start taking combination (estrogen plus progestin) pills late or stop too early (that is, you don't finish the month's worth of pills). If you use a 21-pill pack, you take 3 weeks of hormone pills and go 1 week without pills. If your pills come in packs of 28, the last 7 pills do not have hormones. If you miss a pill right before or right after the week without hormones, you have a greater chance that your body will release an egg (ovulate) and you will become pregnant.

If you do miss a pill, follow these instructions:¹

• If you miss 1 pill, take it as soon as you remember. Take your next pill at the regular time.
• If you miss 2 pills, take 1 of the forgotten pills every 12 hours until you have caught up, then continue taking the rest of the pill pack. Backup contraception is recommended for 7 days.
• If you miss more than 2 pills, skip the missed pills and complete the rest of the pill pack. Backup contraception is recommended until your next menstrual cycle. Taking the rest of the pill pack does not protect you from pregnancy but will control your cycle.

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 18 or older, you can get Plan B from a pharmacist, without a prescription. Bring proof of your age.
• If you are younger than 18, you can get Plan B with a prescription from a doctor.

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. An alternative is to insert the pills directly into your vagina so that absorption through the stomach is not a concern. The pills must be inserted vaginally each day just as you would take a pill orally each day to continue protection against pregnancy.

Talk to your health professional if you are taking medications for epilepsy (phenytoin and barbiturates) or tuberculosis (rifampin). These medications 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 a pill is taken more than 3 hours late, another method of birth control should be used for the next 48 hours to prevent pregnancy. If you forget to take a pill for even one day, you must use a second method of birth control until your next period to prevent pregnancy.² You can't take extra pills as with combination pills to make up for a missed day. Progestin-only pills cannot be used vaginally if you are vomiting because the dose is too low to be effective this way.