Saliva is hypotonic and has been proven to kill the HIV virus, even if you swallow the risk is beyond small because of this reason and because hiv is very temperamental and can't live outside of the body.
actually there is a risk from GIVING unprotected oral sex to someone with HIV, though keep in mind it is much lower, and almost astronomically improbable if he didn't ejaculate in your mouth.
If he came in your mouth I would advise testing, but even still the chances of getting it this way are incredibly remote, so hopefully you don't worry about it.
In terms of HIV, you had no risk according to the experts of this forum. No registered case of infection through this way.
There is a theoretical risk, i.e. it could happen in theory but it has never been determined that it has happened in reality. A number of studies have suggested otherwise. The medical experts on this forum have also stated on numerous occasions that they have never seen a convincing case of transmission of HIV via oral sex.
To confirm what reallyconcerned posted, this was a no risk encounter for the transmission of HIV, but there is always a risk of STD transmission via oral sex.