Put the blame where it belongs--ON YOU!!! You should assume everyone you have sex with is poz and take appropriate actions. You don't know for sure what you did with this guy??? How many guys have you been with? If you're this paranoid about sex you shouldn't be having it. Many people don't even know their status. Do you ask your partners their status? You are the one that's irresponsible and stupid. The good news is that you are probably not infected, but go get tested so you can quit worrying.