A fourth generation hiv test looks for both antigens and antibodies. Your negative results are good news, and in all probability you are hiv negative. Most people seroconvert within the first 3 - 4 weeks after exposure. Since your body has not produced antibodies even after 42 days, and no p24 antigens were detected anywhere during the period between 14 and 30 days (that is when they become measurable.. Check out http://afa.org.sg/what-is-a-4th-gen-hiv-test/ for more details), you are hiv-negative. I would still recommend you to go take a test after 90 days, since that is the recommended guideline. Remember that this 90 day duration is only a conservative estimate for the window period, and an overwhelming majority of people would seroconvert in the first 5-6 weeks.
Never have unprotected sex. Agreeing to have unprotected sex is also consenting to put yourself at risk for HIV.