Braxton Hicks?

Chelsea

So after sex, generally just when I'm on my back, during it I feel sharp pains in my lower abdomen, and they crescendo until we are done having sex and at that point it's enough to make my breathing erratic it hurts so much. It lasts a couple minutes then just fades away. What is this???

I'm 23&4 and a FTM, and it ONLY happens during/after sex.