I know that there are many things you can be tested for and a Rheumatologist can usually figure it out. My ANA tests came back negative and it took three different Rheumatologists over a period of 9 years to even test for Psoriatic Arthritis. My current Rheumatologist figured it out because he tested for the HLA B27 gene. So, I hope that maybe they can finally figure out what is causing your issues and find a solution for you. Please keep us updated and we wish you the best.