About a month ago I had a biopsy. My frist period after the biopsy was fine, and started and ended on normal time, and i refrained from having sex for two weeks after, as instructed. I am on birth control, however this past week, i missed two pills in a row. I took two pills the next day and the day after. My boyfriend and I had unprotected sex around that time( about a week ago). Although he pulled out, i'm still very worried. I was supposed to start my period yesterday, but i still haven't. Could that be because of the biopsy or am i really pregnant?