Rectal pain during sex?

My husband and I were having sex last night and I was on top. We do this position pretty rarely. I noticed the further I got down (ie the wider my legs were around his torso), the more I feel pressure in my rectum. It wasn’t super painful, but definitely a noticeable pinch. I’ve never noticed this (or any pain) before during sex. Is this normal? I have a tilted uterus fwiw.