Talk to Rheumatologist on Pain In Joints

my knees started to hurt few months before i have been through alot of doctors but upto no use my calcuim and vitamen d are normal now my elbow joint and shoulder joints hurt too there is not even a single second i feel better but i have no swelling or anything what could my problem be what could be the reason of low calcuim in bones maybe my blood have calcuim but bones dont what test should be done in this regard