Cramps during sex?

Tori • Married with 2 year old mini me :) B/G twins due 4/2020

Last night when I was on top I started cramping horribly on my left side (upper abdomen) it literally felt like I had a charlie horse there. I hadn't had an orgasm yet so I have no idea what it could be. No bleeding and I was able to finish after taking a break from that position 😂 has this happened to anyone else? I am 27w3d.

Thanks