I know about the lowered effectiveness of birth control while taking penicillin but what if you had sex before starting the antibiotic?

Answer:

If you were still on the pill then you should be fine as not only were you taking it at the time but it also takes time for the contraceptive pill to leave your system. if you are still unsure consult your doctor.

First answer by Pixieangel4. Last edit by Pixieangel4. Contributor trust: 2 [recommend contributor recommended]. Question popularity: 1 [recommend question].