Sharp uterus pain (TMI kinda)

I was just sitting with my daughter on the floor and I got this feeling in my butt like when you have to really poop. Then I got this terrible pain in my uterus area/lower left side and lower back and butt, kind of like bad period cramps. I thought I just had to poop, but I can’t go and this pain is so bad. Not sure if I should call my primary doctor, gynecologist, or what....or maybe it’s nothing?

Note: I’m not pregnant. I’m not due for my period for about 10 or so more days. So I have no idea what this could be...