You don't really need to retest after three months - modern HIV tests are highly reliable after one month.
Given that everything else came back ok, it's very probable that this is going to be ok too. Even if he had HIV, the low risk of getting it from a single incidence of vaginal sex is 'about' one in two thousand - it's higher for anal, but I am making some assumptions about your gender and the sort of sex you're talking about.
It's not impossible that he's going 'Oh no, what did I do with that tourist?!? I hope the test is ok...'