Can't find the cause of pelvic pain on exam or us. Is scope next?

Yes. If you can not find the cause by other means, sometimes it is help to directly look into the pelvis.
Yes. Unfortunately a laparoscopy is probably your next step. It is a surgery, and you don't want the solution to be worse than the problem. I always defer to the patient when we talk about surgery for pain to make sure in their mind the pain they have would be worth having a surgery.