I have the Pre-Order insert (That I got with my preorder from EB Games) in front of me and it says, "You can play upto 5 days early. So, that could as late at the 19th or as early as today. Believe me, I know it sucks. I've been watching endless Live gameplay and I am getting ever more twitchy by the hour. Rub your temples and recite, "Calm Blue Ocean" over and over.
May the Force be with you =)