UTI or HIV?

Hello

Now here is the thing, At first I was urinating frequently and in little amount, after a while the inside of my penis felt itchy and the other day out of no where, I felt nauseated.

Did a urine test and results came out with : "Urinary Tract Infection Site Not" and the doctor said its mild and not that serious prescribed an antibiotic then he kept talking and then he brought up HIV, he kept insisting on it for some reason now what he said was that we still don't know the source and that if the medications didn't work there is a possibility of HIV presence.

My symptoms

Back pain mild

frequent urinating at first it was in little amounts now its back to normal

nausea

 I'm worried but still think its just UTI since he brought it up indirectly all of a sudden dunno really

Could it be HIV?