Hi, thanks for your questions. I am not sure the nature of the exposure risk, if your partner has also had testing done or which HIV tests you had done with blood work sent to the lab so here are a few things to help you decide.
HIV testing done at 5 days post exposure will not cover that exposure as it is too early for the body to make antibodies to HIV or to detect the virus in the blood.
The INSTI test is for HIV antibodies which take some people up to 3 months to form so the absolute window for the that test is 3 months. An INSTI test done at 28 days has approximately a 90% chance of showing HIV antibodies ( positive) if HIV was transmitted.
Usually the HIV test that is done at most labs is also an antibody test so again the window coverage would be at 3 months.
If you had an HIV pooled Naat or early test done that detects the actual virus in the blood then the result for this test is considered accurate at 6 weeks post contact. Hope this helps. Health Nurse