newly diagnosed seronegative R A

I have been diagnosed with seronegative ra after seeing an orthopede, rheumatologist and general practicioners.  I also saw a GI doctor to rule out joint pain from any digestion issues.  I had a hard time accepting that I had ra because I didn't test positive with the ra factor, but did have elevated sed rate.  I have been on prednisone for 5 months, had an allergic reaction to sulfasalazine, no success with mobic or lodine and am now on 5 mg. of prednisone and plaquenil.  I am wondering if there are others with success of this combination and how long it takes to work?