The HIV window period set by the National Center for Disease Control and Prevention is 3 months, but with the continuous development of HIV testing technology, it has been shortened to about 6 weeks. The World Health Organization WHO clearly states that the window period of HIV is 14-21 days. The HIV window period is the period of time after HIV infection when the body has not yet produced antibodies. Although HIV antibodies are not detected during this period, HIV is already present in the body and is contagious. In the past, it was thought that the longest HIV window period could be about 3 months, however, with the continuous improvement of medical testing, the window period of HIV is also gradually shortening. For people at high risk of HIV infection, if you need to test whether your body is infected with HIV, it is recommended to test after the window period to make the test results more accurate. In addition, it is recommended to be clean and avoid impure sexual behavior.