I had unprotected sex with a guy 55 days ago who at the time I know was HIV negative. He slept with a guy 4 weeks ago and was tested 2 weeks ago and diagosed as positive 4 days ago. As he tells me that the guy he slept with 4 weeks ago was safe sex, my question is Did I give him HIV? I was tested yesterday by the doctor with a 1 minute result test with a 28 day window period and my result was negative. I also asked that the blood be sent away for testing and I got the result back this morning - also negative with the same 28 day window. Is it possible that because I could have already been infected when I slept with him 55 days ago and that I was infected less than 3 months ago, passed the virus on to him and that it hasnt yet shown up for me as positive, but will within the next month or so??? Are the 28 day tests always accurate. I am very worried.