Help! Sex/pregnant


Ok so I need your help but first you need a backstory. A few weekends ago my boyfriend and I were drunk and we had unprotected sex. He thinks he pulled out but then again he was drunk. Then we had unprotected sex last night and he pulled out. Then we just fell asleep. When I woke up in the middle of the night my boobs were very big and swollen. Also I take birth control sprintec. So now my questions are

1) how likely am I pregnant?

2) why were my boobs so swollen?

Thank you for your answers!!