Anyone ever experience this: yesterday started out with pain behind my right knee, felt like arthritis which I don't have. As the day went on it spread to my entire leg to the point that I can barely walk. Now my right arm is doing the same thing with it. It's excruciating pain, Tylenol doesn't touch it. The only thing that helps is a warm bath or heat on my leg and arm. I didn't sleep all night and I'm in the tub right now. I'm calling my office first thing but just curious if anyone else has had this. I'm miserable.