Welcome to the discussions and to the world of Macs!
For what it's worth, every single time I have ordered anything from Apple, it has always shipped before their estimated shipping date. That said, this is a brand new machine, so three days is not too long to wait for something that will be in great demand. They will email you the confirmation and the tracking number as soon as it goes out so you will be sure to know when it will arrive.
Make sure you stick around here. There are bound to be a few things that are new to you as a new Mac user and these discussions can help you through just about anything. I think they are one of the best things about being a Mac user.
PS - Michael, where are your manners?! A new Mac user and no "Welcome" - LOL!