Hmmm. There is no harm whatsoever in trying plaquenil, it is very well tolerated. Methotrexate less so, but it is commonly used for RA. How much pain are you in? It takes a while for damage to show up on x-rays. I was diagnosed with everything negative except CRP was 5.6 and SED 56. But I went from "wow this is annoying" to really swollen joint in no time, a couple of months. And once my wrist got that swollen, it took over a year to get the swelling under control (although I avoided steroids).
Anyway, I am sorry that it isn't clearer for you. Normally you might say well just wait 4 months, but a lot could happen in that time. Sorry I'm not much help. I had 100% fine labs in October, when I was feeling miserable, and then everything flared up (well CRP, SED and wrist) 3 months later.
I can say, however, that it is interesting because my sister had ITP when she was 5. She recovered and she doesn't have RA. I have Raynaud's too, and my dad has Addison's (all autoimmune).
Definitley start taking fish oil too, that should help with autoimmune stuff generally, and make sure you are getting enough Vitamin D!