If you pre-registered by mail it will be closer to September when you get your confirmation E-mail.
If you registered by paypal it should already be in your inbox. Did you check your Spam box?
Getting your badge on Friday will take you no longer than 5 minutes, so don't worry about getting it on Thursday. Everyone will still be setting up for the weekend and it'd be too much hassle to have the pre-reg desk open.
{Correct me if I'm mistaken, registration staff.}