A week ago I had unprotected sex with my boyfriend. I am on the pill and take it very regularly. But the next day I unexpectedly had to go to the hospital and was loaded up with all sorts of heavy antibiotics for the next four days. As antibiotics can change the effectiveness of the pill, I am concerned... I got my period today, but it is much lighter than usual. Could I be pregnant?
Well, most antibiotics don’t have effect on birth control pills. Only ones who do are based on penicillin – usually those are the strong ones like ones you were given at the hospital, but even those don’t have those effects always. It also depends on which birth control pills are you taking. Those BC pills containing estrogen are more likely to be affected, but even then it’s not always the case if you are taking the pills on time and don’t skip days. As far as your period is concerned it’s possible that antibiotics changed your period, but that is not permanent or serious.