I took the duo test at 19, 27 & 79th day after the risk which was oral sex by a girl. all negative. can i conclude that i have no hiv 100% ? tks

The HIV "duo" test: is called that because it combines an antibody test for the HIV 1 and 2 strains with a p24 antigen test. It is 99.8% accurate at 28 days increasing to 99.9% accurate at 90 days after potential contact. Apparently in 1/10th of 1 percent, a test could be positive after 79 or 90 days. If my test was negative after 79 days, I would believe I am not infected. PRACTICE SAFE SEX ALWAYS! Good wishes:)