Period like cramps or..

So I was sitting here talking with my MIL all fine and dandy. And she goes outside and takes my daughter with her. (Literally the only time I actually get some piece and quiet lol) and my daughter is 2.5. Anyway. I go to stand up and get this really big pain right in my pelvic area that it caught me by surprise and I had to breathe through it. Me being me just thought maybe it’s the baby moving her head. So now I’m sitting on my yoga ball and it’s just constant period like cramps. I go to the docs tomorrow and am hoping to get checked again to see if I’ve made any progress. I’ll be 37 weeks on Sunday!