Artist, that is a scary possibility for you I would guess. I don't know anything about it, so had to get a quick look about it. I don't suppose there is a way to be sure at this point. I remember being a little confused about the fibro in the beginning. I was sure it was joint pain. It feels like joints, but they say it isn't. I think the tissues, being right next to the bones create the feelings that it is actually the joints for me.
So you have two weeks until you talk to a doctor. maybe It's impossible to put it completely out of your mind, so I can't easily advise that. Just hate to think of you agonizing over it for two weeks, it's a long time to worry and create more stress fro your body to manage. If you can, try to stay busy, I suppose. gentle hug and peaceful thoughts to you.