If you received the first email, we have your preorder stored. It will be processed in the order it was received.
There is no way to check what number you are.
If you're not sure you preordered, dig through your email archives for the initial reciept. If you don't have the email anymore, but have that nagging feeling you preordered, WAIT.
If you have not received an email about your preorder being processed by 8am EST on September 5th, email sales@stardock.com to see what's what.
IF YOU ARE AT ALL UNCERTAIN IF YOU PREORDERED OR NOT, DO NOT PREORDER AGAIN. If you do, you might be charged for two separate orders. Be patient and wait for a little while. At the very worst, you're one day later into the beta.