BH Contractions?

Has anyone gotten BH Contractions in the middle of the night? I notice that when I wake up to move in the middle of the night my stomach will tighten really hard. It doesn’t hurt it just feels weird almost like how it feels when you start getting a cramp in your leg before the actual pain sets in lol. I know dehydration can cause them & since I’m not really drinking any water through the night I can see how that would happen.