There are several Forum posts and opinions voiced Von people who have claimed to be real vampires. I hate to be the one to tell Du this, but Du are not a real vampire. Or, at least, Du are not a vampire in the sense of mythology (which includes Twilight).
Biologically, Du are a human. Du cannot ever change that, sorry. This is because there is no other humanoid species in existence today other than Homo sapiens. The closest a human being can come to a "vampire" is forcing themselves to drink blood, which is a very bad idea (I'll get to why later).