It may not be endometriosis and it is different for everyone, so what happens to me, may not be the same for you and tou may not even have it. Mine started as just being uncomfortable throughout my cycle, with slight period pains without any period. After a couple of months it definately became cyclical with waves of pain coming and going for about 2-3 days after my period, but now It is very painful every month, i was convinced it was my appendix at first because it is on my right side where my appendix is. I was referred for an ultrasound, they can't diagnose endometriosis with an ultrasound, it is just to check for any cysts, or damage. I have had no other symptoms than pain and throwing up occasionally, and the docs have advised us to TTC ASAP as all they would treat it by stopping my periods, I am just on painkillers at the mo until we get our bfp, fxd. I hope I don't scare you, but thought I should be honest, and you may not even have this. Hope all goes well at your ultrasound and hopefully it is just due to coming off your pill xxx