What Causes Pain During Sex And Bowel Movements While Having Retroverted Uterus?

I am a 28 yo currently TTC. For the last few years, during the first day or tow of my period I have had very painful bowel movements (often associated with my heavy days). I do not have other cramps, pelvic pain, pain during sex, and my periods are almost always regular. Sometimes I may be one day early, but thats about it. Whenever I research this symptom endometriosis always comes up, but I don't have any other symptoms. I do have a retroverted uterus. Could this be the cause?