I've read that vampires actually don't like period blood, because period blood is dead blood, and vampires like the fresh stuff.
And also depending on the depiction of the vampire itself, many are described as not being sexually active etc. so they wouldn't need to do this.
Vampires are dumb and make believe! I have no knowledge of such lameness. It makes the joke much better!
I preferred vampires when they didn't have so many rules. These days it seems like they can't step out of doors without being instantly killed/weakened by everyday objects.