I'm on birth control (for like 2 years) and on my second week of pills and my bif snd I just had sex like a day ago and now I think I'm getting sick and need antibiotics. If I start them now can the effectiveness get lower and I get pregnant from the other day even if we didn't have sex while I was on the antibiotics. Like if I don't have sec the rest of the month will I be okay or can using antibiotics now get me pregnant from the previous time?