I have been on the birth control pill ortho tri cyclen for two months now. I take it religiously, never missing a day but I was not informed of the medications that decrease the effectiveness of the pill besides antibiotics and seizure meds. Early Sunday morning I had sex with my boyfriend and he finished inside of me without my consent (I wasn't even aware he had taken the condom off). I did not stress it too much because I am on birth control but I was very uneasy about it because it has never happened before so I looked up anything that could possibly make birth control fail including drug interactions and found that my migraine medicine Fioricet may make the pill less effective. Immediately after finding out, I went to take a Plan B (27 hours after unprotected sex). So my question is what is the chance of pregnancy because I am unaware of how the interactions affect fertility??

P.S I took the Fioricet during the week of the June 26th up until Friday July 1st and had unprotected sex early morning Sunday, July 3rd (around 3am)