It is recommended to test once a month or once every three months after high-risk behavior. Taking HIV-blocking medication does not completely rule out HIV infection. Therefore, viral testing is still needed. It is recommended to check for HIV antibodies one month after high-risk behavior and again three months later. If the test is completely negative, HIV infection can basically be ruled out. If you take HIV blocking drugs in time after high-risk behavior, you can effectively block the transmission of HIV and reduce the possibility of HIV infection to a greater extent, but it is recommended that you still need to take the relevant tests to be able to rule out the possibility of HIV infection. HIV can be transmitted through blood contact, sexual contact, and mother-to-child transmission. It is important to avoid these modes of transmission.