Halloween: Turned into a Vampire

It is Halloween today and after a day of studying at college you head to your apartment and find a package on your bed. Inside is your Vampire costume for the Halloween party tonight but you also see a necklace with a ruby gemstone that you don't remember ordering and you put on the necklace and you turn into a Vampire. It turns out that it was not a ruby necklace but a necklace infused with the blood of a Vampire.