You didn't have a risk. Unless you had unprotected vaginal or anal sex with this partner, you didn't place yourself at risk for HIV. I understand it is frightening to find out after the fact that someone you were intimate with is infected, but don't let fear guide you based on that. You have to look at the FACTS, and the FACTS are, almost ALWAYS, it takes insertive, unprotected intercourse (a penis in the vagina or anus) to lead to transmission (or sharing IV drug works). And believe it or not, even mosrt unprotected exposures don't typically lead to infection, HIV is THAT difficult to transmit.
Testing is understandable in your situation, just as a way to put your mind at ease. A DUO test at 4 weeks will be very reassuring. If you had been infected, the DUO test at 4 weeks would almost definitively be reactive. Follow that up with a standard antibody test (ELISA) at 3 months post the incident for a conclusive result.
I have no doubt your results will be negative. Until the conclusive testing, keep yourself busy and definitely don't search the internet, as that will only fuel your anxiety terribly.
If it will be helpful, you can always pay the nominal fee (I believe it is about $22) to post in the expert forum. The docs there will put your mind at ease. They have DECADES of experience working with HIV.