Upper/Mid abdominal pain

I’m 35 weeks and for about 3 hours I’ve been having a real bad stomach pain, almost like a bad cramp in the middle/upper part of my stomach. I was able to sleep for about an hour after it initially started but it has become more intense and starting to hurt more & more. It doesn’t feel like a contraction because I don’t feel any tightening however it does come in waves. Does anybody know what this could be?