Weird.. Painful sex experience

My boyfriend and I were having sex earlier today, he was on top of me with my legs up in the air on his shoulders. I suddenly received a horrible, painful sharp pain that went up across my left ovary area. It hurt so bad I started to cry.. It lasted for a couple of minutes. We've had sex in that position many times and I've never experienced anything like this before. It freaked my boyfriend out and he felt so bad. It almost felt like a period cramp just 10X worse. Has anyone ever experienced this before or have any idea what it could be?