Yesterday My arm was bitten by a mosquito,and i think i had scratched that place,it turned red amd looked like a wound,but it didn't bleed.About 7 minutes later,I went to the stadium to meet my friend,when I got there,my friend was swinging his hands,and I definitely saw his hands bleeding,I felt some kind of stuff drop on the wound i have mentioned before,I just keep wondering whether it could be my friend's blood,and if so,am I at a risk?(My friend often has unprotected sex) One thing I can make sure is my wound wasn't bleeding,but it remains red until now.