Antibody tests can usually detect HIV 23 to 90 days after exposure. Most rapid tests and self-tests are antibody tests. A rapid antigen/antibody test done with blood from a finger stick can usually detect HIV 18 to 90 days after exposure. An antigen/antibody lab test using blood from a vein can usually detect HIV 18 to 45 days after exposure. A nucleic acid test (NAT) can usually detect HIV 10 to 33 days after exposure. Download and Share If you get an HIV test after a potential HIV exposure and the result is negative, get tested again after the window period for the test you took. Learn more about what a negative test result means.