constant tightness / cramps / upset stomach

Heather
I'm 31 weeks and 2 days. Since last night I've felt like I've had an upset stomach and tightness/ cramps. It doesn't come and go so didn't think was BH or real
Contractions. But it's constant. I thought for a while it was gas or constipation /
Something to do w digestive system or stomach. But idk. Right now it's the front of my belly low. 
I was in labor and delivery yesterday for 2 hours / monitored bc of
My bp and it was fine. And then later that night the cramps stuff started. I went to work etc. but just feel like crap