I've "lost" confirmation emails before as well, I'm not sure if they were just never sent or my email filtered them out and the spam folder was automatically cleared before I could resurrect it but as long as your order history page has confirmation of the order and it has a pending status on it you should be fine. Also, check if all of your items are kept in stock. If you're purchasing an item that they have to acquire first it can take 30 days or more for them to even receive the items and then prepare for shipping.