I just cut my thunk on a knife that came in the mail. i'm nervous about hiv as i do not know where the knife came from. it was a gift and was not wrapped at all just in a box. should i be concerned? freaking out a bit.

Not for HIV: HIV is a very fragile virus and is killed very quickly outside of the human body so the chances of getting HIV from the method you describe is very unlikely. However there are still concerns of other problems such as bacterial infection and tetanus, if the knife is rusty or the cut was deep, the area because red/hot/swollen please seek medical treatment.