Okay so I am really shy about this kind of thing but I will do my best to explain the situation. I have researched this to death but I don't seem to be getting a clear answer.
Okay, today is Sunday and I just got back from a weekend with my boyfriend. On Friday, we had unprotected sex but due to paranoia on both parts, it only lasted for about 5-10 minutes before we stopped. It didn't happen again until Saturday night and, since we didn't learn our lesson the first time we managed to have it happen again two more times, each lasting a bit longer (15-20 minutes tops). He never ejaculated but I know that precum MAY contain sperm. So that was three times within the last 48 hours that this has happened.
Again, due to paranoia, I stopped on the way home and got Plan B (which is effective up to 72 hours after unprotected sex). I have only taken the first pill and I am due to take the other one later today.
I know that there is a small window in which pregnancy can occur, and mine would have been LAST weekend (if it is 14 days after the first day of your last period). My period is supposed to start on May 11th (if that helps).

I guess my main concern is that I got pregnant before I started taking the Plan B. So. This is where I need advice. First of all, is it even possible that I could have gotten pregnant from precum. Second of all, could I have gotten pregnant before I took the Plan B (emergency contraceptive). Every opinion counts... wish me luck!