I suppose U have pain in the back..
U r tested positive for HLA- B27..
With your history & age U can probably have ankylosing spondylitis which is autoimmune condition affecting lower spine & Sacro iliac joints.
U should probably have morning stiffness in your spine. Needs further evaluation..
Next Steps
Best person to treat is Rheumatologist.
Dr.Sarat Chandra Mouli KIMS Minister road,Secunderabad