So AFAA has two different things: a membership and a certification. You should receive two different packages.
The first being the membership, which is an annual payment and qualifies you for AFAA member discounts and access to the American Fitness magazine. With that you’ll receive a member card and id number.
The second package should contain all the information on your certification. It will contain a card or two with your certification information, as well as a certificate of having passed and information on your renewal.
I know its a bit confusing, but that’s how AFAA operates their program. I hope that helps. If you have any concerns or questions, I’d contact them directly. They’ve always been extremely helpful when I’ve had any questions or issues in the past.