i'm not an expert but noticed no one has replied to you so thought i would try to help as much as i can. with you testing negative twice chances are you got very lucky. i have heard that it is harder for a heterosexual man to catch the hiv virus than it is for a hetero woman. still don't quite understand it, but that is whats said. i don't know anything about the saliva test, i know that the blood test is supposed to be acurate, but i honestly know nothing about the saliva test. sorry. also chances with a one time encounter are pretty slim, from what i hear..... but some people catch it after only being exposed to it once. so in my opinion thats something hard to say for sure. i would say it depends on the person subjected to the disease more than the disease itself. i personally do not go by statistics, because everybody varies in how their body responds to things. i would say, if the 2 test you've already have still haven't satisfied you, wait a few onths and do one more. but don't keep stressing over it. sometimes just by stressing over something our bodies can play horrible tricks on us. just be more careful for now on. make sure the condom comes first. there are other diseases out there, and some are extremely easy to catch.... for example, herpes. i hope you get to feeling better, and i hope i was of some help. sorry i couldn't have been more. i will keep you in my prayers, and take care of yourself. God bless!