Hello dear friends,about 4 years ago i was involved in a series of unprotected sex with a woman that included anal penetration,two years after the incident i got tested with negative result,again 1 year after the first test i decided to go to another lab and get tested,that time negative as well..its been 6 years now and i was wondering if its possible that the test results weren't reliable and i need to do something else just to make sure.