It is unlikely that your flu-like illness is due to HIV. It has occurred too late following the exposure you describe.
We do not recommend PCR tests for HIV diagnosis. The are not approved for this purpose and they clearly have problems with false positive test results. Less is known about how well they work for diagnosing the infection or precisely when they turn positive. I am sure that whomever you bought this test from will tell you that their results are accurate and indeed, they probably are. If you had had a negative antibody test at this time, I would tell you the same thing. As for the HIV PCR, as I said, this is probably good evidence that you do not have HIV but I cannot tell this with assurance based on scientific studies. This is particularly true as your encounter was very, very low risk to start with. EWH