Hi! Well, Me And My Boyfriend Have Had Sex Not

Hi! Well, me and my boyfriend have had sex not for the first time but we had sex TWICE Sunday. This was the first time we have done that and now I feel bloated and am getting sharp pains and like a constant pressure in my abdomen. We used a condom and he didn't get off in me, plus we checked the condoms afterwards to make sure they were not busted which they werent. So I'm not pregnant. So what's causing this?