HIV Testing. First, there is no test that pick up HIV until it has become an infection in the whole body. This is usually between two to three weeks after an exposure and is known as viremia. The HIV RNA pcr test can be 100% accurate if the time for viremia has passed. The antibody tests, otherwise, are accurate when the human has created antibodies and this can happen from twelve to twenty-four weeks after.
Depends on the type. Of test. There are at least three different types of tests for hiv. Hiv nucleic acid test is the earliest to turn positive, usually in less than three months from the time of infection, usually by 3-4 weeks. See this site for more info on the subject. http://www.cdc.gov/hiv/basics/testing.html.