you had contact with someone who has aids, and you're worried.
checking your blood pressure, relax.
the hiv virus can only be transmitted through the exchange of bodily fluids, namely blood and semen.
leave that.
we're going to draw blood.
joe. i don't care a whit about your private life.
right.
not by touching, or shaking hands, or hugging, using the same toilet.  even kissing someone with aids is safe. but it there's something in your past you're worried about.
a homosexual encounter.
unprotected sex with a prostitute.
or unprotected sex with someone you didn't know very well, any time during the last twelve years.