Could Swelling In Ankles And Knee Be Related To Elevated ESR Levels?

I FEMALE 34 YRS AGE , SUFFERING FROM BOTH ANKLES & KNEE PAIN , SYNOVIAL SWELLING OF BOTH ANKLES , SWELLING OF LOWER 1/3 OF BOTH LEGS ,ALL BLOOD TESTS ARE NORMAL RHEUMATOID FACTOR , CRP , ANTI CCP ANTI BODY NEGATIVE , ONLY ASO TITRE & ESR ARE RAISED .. WHAT SUD I DO ??