It is not possible to test for HIV when you are first infected because it takes a certain amount of time from the time you are infected to the time you can detect it, and the time in between is called the window period. If you want to be tested for AIDS, you should do it after the window period. Most hospitals in China test for AIDS antibodies, which can be detected in the body of an infected person about 3-4 weeks after infection. If the test is for P24 antigen, it only takes 2-3 weeks to be detected in the infected person’s body. In the case of HIV-RNA, it takes only 7-10 days to be detected in the body of the infected person.