HIV can be present in great quantities in both sperm or vaginal secretions. During the vaginal sex there is friction between the vaginal walls' mucosa and the penis's skin. The friction always causes micro-lesions on both surfaces that are not visible but still big enough for HIV to pass through. I seems that in your case the risk for HIV-transmission was low because even if vaginal secretions touched the penis's skin, the condom prevented lesions on the penis's skin from occurring.





The p24 test is generally only positive from about 1 week to 3 - 4 weeks after infection with HIV. The p24 protein cannot be detected until about a week after infection with HIV because it generally takes that long for the virus to become established and multiply to sufficient numbers that they can be detected. The p24 proteins then become undetectable again after sufficient antibodies to HIV have been produced because they bind to the p24 protein and eliminate it from the blood. You could have waited for a few more days before you took a p24-test. Now you may repeat the p24-test so that the results become valuable.