I had the same tests and a normal result just rules out other concerns so it points towards MP based upon symptoms. I have been told the same for other tests and scans, they are all just used to rule out other prognosis. There is on conclusive test for MP the closest tool they use is a nerve block, if it works it points towards nerve compression.
Suggest you read as much material as possible on MP as many doctors and other health care workers don't know much about it. I wish you luck in finding some relief.