Taking certain antibiotics will decrease the effectiveness of your birth control pills. It is impossible to know how much of a decrease of effectiveness has occurred. Antibiotics may decrease the effectiveness enough to allow a “break through” ovulation to occur. This could result in pregnancy if one has unprotected sex. It is best to use condoms during the time that you are on the antibiotics and for at least 7 days after completion of the antibiotics. If this occurred recently, Plan B may be an option.
Continue taking your pills correctly and consistently. If you are still on antibiotics, use condoms for the rest of the cycle. If your next period is more than 1 week late, do a pregnancy test.
11. February 2012
anonymous-qa