I had sexual intercourse with my boyfriend and he didn't use a condom. I used Plan B and hour later but days prior to that had taken Amoxicillin, and the morning after I had taken it. About a week after, I saw bright red and dark red blood coming out of me and I mistook as my period, but it eventually turned dark brown, nearly blood and did not flow like a period. That being said, I started taking my birth control because of it, but I'm sure it wasn't. Could I be pregnant? What do I do about the birth control? Should I continue taking it?