Will the pill affect my MRI scan results for endometriosis?

My doctor has finally referred me after over fifteen years of pain and symptoms, suspecting potential endometriosis. I take the pill back to back to control my symptoms (which works to an extent), will taking the pill make it more difficult for anything to show up on an MRI if I have endometriosis? (Will it make it smaller or less inflamed?) I have waited so long and been ignored by so many doctors, I want to make sure my results are accurate. The doctor is reluctant to do a laparoscopy as well.
Has anyone else have any experience with this? They haven’t given me any information at all, just sent me a letter with the appointment date.
Thanks for any help and advice!