Yea that’s my instinct too but of all the things I’ve accomplished, med school wasn’t one of them. 🙂
My blood test wasn’t positive for RA Factor until 7 years after I had been diagnosed - autoimmune disorders don’t always make it easy in terms of diagnosis. Sometimes it’s based on inflammation indicators measured by sedimentation rate (esr) and not much else to start.
I’d try to see a Rheumatologist.
Where are you located? If you don’t mind saying that is. Someone here may know a good one - tho it may be months until you can get in as a new patient.