Birth Control: If You Miss a Pill

Kelly Anne Spratt, D.O., Director of Women's Cardiovascular Health at the University of Pennsylvania Presbyterian Medical Center, answers your questions.

Q. Two weeks ago I forgot to take my birth control pill one day, and did not notice until the following day. I took two pills that night and have been taking them regularly since that time. Now I am late for my period and I want to know my chances of being pregnant, and what kind of risk I took by continuing with the pills.

A. Start by taking a home pregnancy test. Then be sure to check with your health care provider.

You were absolutely correct in doubling up on your pills the following day. In most cases, if you miss only one day the risk of pregnancy is very low -- especially if you have been on the pills for longer than a few months. The risk is certainly less than 5 percent.

If you forget during another cycle, to be on the safe side use a backup method of birth control until your next period.

For women who have missed more than one day, or for whom another method of birth control has failed (a broken condom, for example), taking a larger dose of some types of birth control pills within 72 hours of contraception may prevent pregnancy. This is the idea behind the so-called "morning after" pill or emergency contraception.

Not all birth control pills can be used as an emergency contraceptive, and the side effects can include nausea and vomiting -- so this is not a good routine method of birth control. A toll-free emergency contraception hotline provides 24-hour automated information on emergency contraceptive methods: 888-NOT-2-LATE. Or visit the following Web site: