Suspected endo

Hey guys! I am now 18, I feel that because of my age, my pain and worries have just been put aside. For the past 4 years i have had extremely painful periods, heavy periods lasting 12-20 days, have pain going to the toilet, have pain during and after sex and bleeding after as well. I have been put on waiting list after waiting list, I have gone to a gyno who first, put the rod in (implant), that didn’t work, put the mirena in, it has made my periods lighter but hasn’t helped painwise. He suspected endo however said I needed to have the mirena for a least a year and a half before he can actually check. I’ve had scans taken and have been told over and over again that everything is fine but I know my body and I know it’s not normal for me to be in so much pain.

My period started on Friday, I have taken 3 days off work due to cramps and vomiting because of my cramps. I went to the doctor yesterday and I have been booked for a pelvic ultrasound and I am finally getting a lap procedure to get a proper diagnosis. Is there anything I should know prior to the procedure and after? I am so scared but so relieved to finally been taken seriously.

Tia xx