Suggest Treatment For Pain At The Back Of Right Knee

hi! iam Samiha..a week ago, i had swelling in my index finger in my right hand, and the next day my whole hand was in severe pain-elbow down..the same day two fingers on my right hand started swelling and were in severe pain.the same day at night, i had bruising in my both palms along with swelling and pain.. i started taking pain killers, they weren't seem to be working..iam also allergic to ibubrufen..i was getting treatment for the swelling and pain, just then i had severe unbearable pain pain at the back of my right knee..i have been going to doctors..my doc prescribed some tests to check if i had rheumatoid arthritis, the Q.R.A test is negative along with antibody to cyclic citrullinated peptide test-the result was<7...iam sooo confused...dont know what to do...pls help