TMI, but extra rectal pressure...

Nothing seemed to be out of the ordinary until today. Had what I thought were BH- mild, and one or two spread out over time- this early afternoon, had sex and some time after I’ve started experiencing lots of rectal pressure and pain. Some pressure in my vaginal region, but mostly my rectum area. It feels as though I’m trying to push him out from my butt without even trying, or like everything is stretched and about to give any moment. My hips aren’t in any pain, and my last appointment my OB said he was pretty low, pointing to where his head was. I’m 36 weeks and a FTM. Should I call it in to let them know I’m experiencing this or just let it be and see if it subsides? Thanks!