We did an add-on by mail several years ago. Just for my piece of mind, I called to make sure they received the papers after a week. It really never hurts to check - in case something DID happen to get lost (I guess they still use FedEx?) As good as the courier servies are, mistakes do happen.
Really, if this is your initial purchase, a Quality Assurance person should call (or maybe they called before you returned the papers?) to see if you had any questions.