Joshoo, I had a knowledgeable PCP that looked not only for the RF factor but several other markers that can give a definite diagnosis. One of my markers was a high C-reactive protein, elevated EOS and of course white blood cell count.
If you have a physician that only looks at a positive RA factor for an RA diagnosis, with all due respect, find another Dr. Most of the time a Rheumatology visit must have a referral from your PCP. If this is your case, a Family or General Practitioner can still order the tests.
If you find a quality Rheumatologist, they will test for EVERY autoimmune disease known to Medicine because autoimmune diseases often work in groups. When a patient is found to have one, a 2nd and 3rd are often diagnosed within the first several yrs of the 1st diagnosis.
Hang in there! It took me 3 yrs to get a positive diagnosis and the disease had already affected my eyes, connective tissues, ligaments and tendons leading to emergency knee surgery when, without warning, while I was simply standing, texting on my phone, there was a loud pop in my knee and I couldn't walk....at least until surgery.
Let us know,
Debbie