The diagnosis of the asymptomatic stage of HIV infection is confirmed mainly by a blood test for HIV antibodies. HIV antibodies can usually be detected by a blood test after a window period. The average window period is four to six weeks, and in some patients it can be as long as six months. If you have had unclean sexual intercourse, a blood test three months later will usually reveal HIV antibodies. If you have repeatedly had unclean sex and have not been tested for HIV after three months, it is recommended that you be retested after another three months. If HIV antibodies are not detected after six months, it is unlikely to be infected with HIV. Be clean and seek medical attention if you have high-risk sexual behavior. Before HIV enters the AIDS stage, it is possible to significantly delay the time to enter the AIDS stage if you go through regular antiviral treatment.