Rheumatoid Arthritis is a lifelong incureable disease.  That being said, you can experience periods of remission where you have no pain, or little pain, and good blood tests.  However, it is very possible to be misdiagnosed.  You may also have conflicting opinions from different doctors.  You may want to get a second opinion, just to make sure you are getting adequate treatment for the right condition.  The blood tests that are used to diagnose RA can be positive for many other conditions as well.  Sit down with your doctor and have him explain exactly what made him change his diagnosis.  If you speak with your doctor and still feel that you may have RA, I would recommend you get a second opinion.  Good luck, and best wishes!