Pain???

So last night my fiancé & I were having sex, and I got this sharp pain in my lower left side, that lasted a while. Then we finished & about an hour later went for round 2, I was fine that round but after we finished my stomach kept getting hard and every time it got hard it was painful. This lasted HOURS. Probably 3-4 hours. Anybody know what it could have been? Maybe Braxton hicks ? I'm fine now