Your test will be reliable at this point. I am not sure if you have solid reasons to suspect him to be HIV positive. Normally, not every one around is HIV positive.
Hypothetically if he is infected and this was the only unprotected exposure, odds of transmission in MTF scenario is 1 in 1250, if you are from a high income country and 1 in 333 if you are from a low income nation.
We wish you good luck.