Sue,
First of all - again, it would be for the best of all of us if you would get better on that drug - Because we care about you, and also because we look anxiously for a treatment for ourselves.
I hope you would improve during that month - but as people said here, it's very much possible that it would take some more several months for that improvement. I hope your doctor would agree to continue your prescription even when you tell him about your negative serology tes results. I would live one question to the specialists here, and that question is whether or not taking AZT for to months and raltegravir for one of those months, and than stopping, might cause resistance to the drug (definitley hope that it's not possible - and even if it is possible, I guess there are more people that wouldn't develop resistance than people that would). Does it matter, for that issue, that XMRV is a simple retrovirus that seems to not be mutating a lot?
One more suggestion for you, Sue, similar to what I've said a couple of days ago (before you got your new prescription): You might want to look all over the internet for a doctor who is willing to prescribe antiretrovirals to ME/CFS patients (may be even better if it's a doctor who did so even before the XMRV connection was discovered - because than your serology test should not matter) - And get an appointment to that doctor - perhaps an appointment that you would be able to cancel if your current doctor would continue your prescriptions - and if your current doctor would not agree to give you new prescriptions for antiretrovirals - than maybe that other doctor would agree and you would be able to continue to take your antiretrovirals without stopping (which, I guess, might be critical).