See the print products page for a link to the order status. If you are not in the US,replace /us/ in the link be thecode for your country.
Since you did not receive an email confirmation, check, if your emal is working. Have you previewed you book before ordering? If the book contains corrupted media files, it may not upload. And if there are problematic fonts or something, the Apple Print Products Store may cancel the order witthout sending a confirmation. So check the preview carefully and save the PDF: