Is this endometriosis


I have been on nexplanon for 2 1-2 year and when I finally got off it my cycle 3months to come .. then when it did horrible pain and heavy bleeding came with it .. to where I called out of work a lot and could barely move to where I had to go to the er ... it pops up after sex sometimes I’m going to a gyno now and she thinks it’s some thing GI related but I just know it’s not .. help please 😞😞😞😞😞❗️