Your risk is ZERO, no matter what. You cannot get HIV from objects, even if they have blood or other fluid on them. HIV is transferred directly from person-to-person, and not via objects. The only exception is sharing intravenous injection needles, and that is because the liquid blood is held in a vacuum (the syringe).
Do not have unprotected, penetrative anal or vaginal sex with someone of unknown HIV status, and do not share intravenous needles, and you will NEVER have to worry about HIV.