HIV can have a very long incubation period after it infects the body, with the shortest incubation period being about four years. Therefore, if HIV infection occurred during high-risk sex four years ago, it cannot be ruled out that HIV infection occurred during these four years without any tests and without any uncomfortable symptoms. If the incubation period of AIDS is eight years on average, there will be no symptoms in the next few years; if the incubation period of AIDS is more than ten years, there will not be any uncomfortable symptoms in the next ten years or even nearly ten years. So if you want to rule out any worries in this regard, you should go to the hospital for an HIV antibody test, and it is perfectly fine to use HIV test strips, such as blood, saliva or urine test strips for primary screening.