My wife has been through the ringer
for the past 4 months, taking more blood tests, xrays, ultrasounds, etc than I care to remember. He joint pain in her fingers, knees, ankles and shoulders are pretty constant, though she just had an amazing pain-free 3 weeks. It just came back over the weekend, leaving her depressed and frustrated.
My point is, the only test that she has tested positive for is HLA-B27, suggesting possible reactive arthritis.