Menstrual cramps after BM

I know this is so TMI but I've never experienced this before. I'm 12dpo today and expected AF is due Friday 9/15. Ever since Sunday 9dpo I've had cramping in my uterus after a bowel movement. At first it was very mild but yesterday felt a little more painful. The cramping only lasts 5-10 minutes max and then I feel fine. I tried googling and all I came across was articles discussing endometriosis or women who were far along in pregnancy. I know 100% that I don't have endometriosis. I'm wondering if this could potentially be a early pregnancy symptom for me. I'm going to wait until I miss AF before taking a test. Anyone ever experienced something like this?