After HIV infection, the positive rate of HIV antigen and antibody combination test in 2 weeks is generally about 50%-60%. Because there is a certain time interval between HIV infection and antibody production, it may take more than 3 weeks or up to 3 months to test positive for antibodies alone, but if nucleic acid is checked, it may produce positive results in about 1 week. If the test is negative in 2 weeks and there is high-risk behavior, it is usually recommended to retest again in about 3 months. If the test is still negative around 3 months, HIV infection is completely ruled out.