Ive been with my bf for 6 months,just found out hes been hiv positive for 4 year's,why did mines come out negative do i have it as well?

Communication: It's very important to talk to your partner about health. If he's been positive for HIV for 4 years-has he been on medication? That's very important. Also, what about protection? ID doctors specialize in this kind of thing-so good to have some conversations with the doc taking care of your BF, with you along for the apt. There's a lot that can be done these days for HIV discordant couples.