When an HIV-infected person converts from HIV negative to HIV positive by blood testing. Shortly after infection with HIV, the body begins to produce HIV antibodies. It takes the body a while to produce enough antibodies to be detected by an HIV antibody test—usually 10 to 14 days but sometimes up to 6 months. When HIV antibodies in the blood reach a detectable level, the HIV-infected person seroconverts. In other words, the person’s antibody test goes from HIV negative to HIV positive.