soldier61,
Though it is true that there is seronegative rheumatoid arthritis, it does have other parameters. Since it is an inflammatory disorder, the patient's ESR (erythrocyte sedimentation rate) and CRP (C reactive protein) would be elevated. You state that yours were within normal limits.
Also, persons with inflammatory arthritis do present with pain, they also have inflammation of the synovial lining of the joints. This is manifested by swelling, effusions, and bogginess of the joints.
Unfortunately, there are many, many inflammatory processes, and most do not have any type of serological markers. They are all based upon history and the physical findings.
You may have a very early stage of an inflammatory arthropathy, but until symptoms other than just pain show up, a definitive diagnosis may not be possible.
Beginning treatment of the inflammatory disorders is with NSAIDs. You have probably tried them. If they did not help your pain, you probably don't have an inflammatory process. It may be possible that you have fibromyalgia, which is overactivation of the nerves, causing widespread pain. But, a rheumatologist should have been able to diagnosis this disorder also.
Sorry, but you are sort of in that position, that until further symptoms show up, you will have to treat this symptomatically.
You can try keeping a journal of your symptoms; when they are the worst, what is associated with making them worse or better, which medicines/therapies seems to help the most, any other symptoms (swelling, redness, decreased range of motion, numbness/tingling, etc), is the pain worse in the morning (and gets better with activity) or is it better in the morning (and gets worse with activity), and anything else that you think plays into the problem. Then, the next time you see the rheumatologist, take the journal with you. Often patterns of symptoms are very important in making a diagnosis.
Hope you find the cause of your symptoms. Good luck.