To the best of my knowledge, every C-card you get will have a different diver # on it. As long as your name and birthdate are the same (exactly), all of those certs should be under your profile with PADI. You can also set up an online profile on PADI's website. Once you do, you will be able to see all of your existing certs. If any don't show up, you can contact PADI to find out why, and they will correct it for you. My wife had one cert not show up on hers. It turned out it was because the instructor misspelled her last name on an online application. Problem was resolved in a matter of days. Enjoy!