I went to a barbar shop where I regularly go. There is a general practice after having hair cut they will shape back side of neck with razor. He usually changes the blade, but this time I did not pay attention. I had a small pimple and he ran razor on it by mistake. Nothing serious on bleeding, just minute blood like when pimple breaks it comes. Random thought has struck me - is it possible to get HIV like this? Little worried...please help.