AIDS can be ruled out for six months. For the diagnosis of AIDS, the general rule is to check the AIDS antibody, if the antibody is positive, the infection may be considered and further confirmatory tests are needed; if the confirmatory tests are also positive, the diagnosis is clear. Of course, there is a time period for the production of antibodies, which is often called the window period, usually about 2-3 months, some people may be shorter, about 2 weeks will produce antibodies. Of course, some people may be a little later, even up to about 3 months. If the HIV antibody is negative within six months, HIV infection is ruled out.