You might have ordered from another Adobe account. Check and confirm that the email address on which you received the reminder is the same as the Adobe account from which you ordered.

Do you have more than one subscription?

If you have more than one subscription, Adobe sends you payment reminders separately for each of them.  

View your subscriptions on the Plans tab of your Adobe account and check if payment is pending on any of them.

Note:

If you have subscriptions on different Adobe accounts (usually your email addresses), you might have received a payment reminder for a subscription on another Adobe account. Ensure that you are signed in to your Adobe account with the correct Adobe ID.

Did your credit card details change recently?

If your credit card details (for example the expiration date or address) have changed, you would have received a reminder because the payment could not be processed. Learn how to view and update your card details.