That story of not expecting to be positive but finding out that you are, is pretty common. I am being tested and waiting for the results at the moment. I don't expect to test positive, but so many people do that I guess I wouldn't be surprised. I really hope your treatment works. You may have to try a few things, but given a bit of time you've probably got a good chance of some improvement. One of the papers I read talked about a link bettween Borrelia fragments (where the living organism has been killed off by antibiotics or the immune system) in the joins and continuing to cause arthritis, even after Borrelia was no longer detectable in the blood (dont quote me on that though because my brain is foggy today and it was just something I skim read a while back). I don't think this is the case for everyone though, so hopefully your symptoms will all improve.