The doctor needs to be reminded that anyone with clinical symptoms consistant with Lyme and known exposure to a tick in a Lyme-endemic area should be treated. Even the CDC says the test is only meant for tracking purposes and is not intended for diagnostic purposes.
Another thought is to try an antibiotic challenge. This serves 2 purposes:
1) If you herx on abx, you have Lyme. But not everyone herxes on abx. Also, if you feel better on abx, then there is obviously something going on that requires antibacterial treatment (or anti-inflammatory treatment). Be sure that the abx you are given is given in a theraputic dose for Lyme. Doxycycline needs to be at least 400mg total per day (some LLMD's like to give more than that).
2) If you test (IGeneX) after being on a short burst of abx, then the test may show more bands positive. Call IGeneX to find out how to do this type of testing - there are protocols for how long to take abx and how long to be off of them before retesting.
See the following for more info on why Lyme tests are not good enough by themselves to be relied upon for Lyme diagnosis:
http://www.anapsid.org/lyme/lymeseroneg.html
http://www.canlyme.com/flawedtest.html
http://www.canlyme.com/labtests.html
http://www.canlyme.com/wb.html