RA symptoms. My ra factor level?

My maternal uncle has ankylosing spondylitis and my paternal grandmother had RA . My RA factor is 20.6(positive) and my ESR is 19 but my anti ccp , crp , ASO , ANA and CBC are all normal . Also HLA-B27 negative I was sitting in my chair one day and suddenly I felt a sharp pain in my upper back which after 2 days got ok but the pain shifted to my lower back and since then it is there . My low back pain is therefore for about 5 months now despite having muscle relaxants . Apart from the lower back pain i don't feel any other pain but feel a little stiffness in my fingers and neck but they don't hurt when i press them nor are they swollen . I wanted to know the exact symptoms of RA and do i have it ?? Does RA effect lower back ?? Also i drink a lot of cold drinks so can it increase my RA factor level ??