Pooping during 3rd trimester

I'm 32 weeks and have never had issues with constipation during my entire pregnancy.

I poop regularly. But, everyone I need to poop I have these intense cramps and I am always thinking...this is it. It's contractions. So I sit for a second and then I realize I need to poop. So I go and poop. I have no issue getting it out at all. It's not diarrhea either. But why does my stomach cramp so much when I need to go? I get so scared lol. These cramps hurt so badly everywhere in my stomach that I can't distinguish them. Does anyone else have this issue?