False positive p24 test for HIV

Dear Ask The Doctor: Hello doctor, i read the above blogs but i did not see anybdoy having being tested false positve as is in my case, my story goes like this...i had unprotected vaginal sex with a male of unknown hiv status.3 months later my elisa and p24 was positve but negatve western blot.i went to hiv specialist who ordered new tests elisa western blot p24 and hiv dna pcr...all came back as negative..i waited another 6 mmonths and did a western blot and it was negative.am i hiv free doc?can p24 give false positve as it did in my case in the beginning?

Dear Nadia: The Western blot is the most commonly used assay to confirm a positive rapid test. This test sequence has a a sensitivity of 99% and more than 99.9% specificity. False negative results may appear if the test is conducted between the time of viral transmission and seroconversion. However since your repeat western blot was negative after 6 months, it is safe to say that you do no have the disease. Antibodies to p24 have been detected in 1 out of 150 healthy individuals. Conversely, the p24 antigen is not found in all HIV positive or even AIDS patients. The p24 test is clinically erratic and should be interpreted very cautiously.