Family Planning Plus

It is true that some antibiotics can decrease the effectiveness of your birth control pills.  The concern is if the antibiotic will lower the pills’ effectiveness enough to allow your body to have a “break through” ovulation. How much of a decrease it causes is unknown. Since there isn’t much research on specific antibiotics and their effects on oral contraceptive use, we recommend using a back up method while on all antibiotics. Using condoms or abstinence during the time you are on the antibiotic and for 7 days after completion of the medication is the general rule.

So, at this point, you’ve done all you can do. You’ve continued taking your daily birth control pills and you took Plan B. Plan B can reduce the risk of pregnancy by 75 to 80%. Keep in mind that after taking Plan B, you may experience some irregular bleeding or spotting. Your next period may come a little earlier or later than usual. It may be lighter, heavier or spottier than usual. If your period is more than a week late, do a pregnancy test.