The type of encounter that you had presented zero risk for transmission. You are not positive. I don’t believe that any medicines or other health conditions have impacted this test. If, by some chance, you are infected, it was not from this encounter but at this point,I think you should consider yourself uninfected. You can do the blot if you are worried, at 12 weeks out from the encounter. It takes about 10 day to get the kit so you could start the process now if you wish to take the test.