Camping after peeing.

Bri • I'm me 💯💯💯🎀
I'm 23 weeks and sometimes after I pee I immediately cramp so bad I have to lean over. I don't know if baby is sitting on my bladder or what but it feels better as soon as I sit down and if I stand back up I feel it untill she moves I think. Have anyone felt this before.? It doesn't happen all the time but it does happen often.