Welcome to the Community. I'm here to help you determine the status of a credit card payment in QuickBooks Online.
If you're referring to the credit card payments processed through an emailed invoice, you can check the status of the charge through the Merchant Service Center. You can also check the progress of your invoices through the Transaction list section within your QuickBooks account.
In case you want to know more about what happens with the payments, I'm adding the article I recommend on this (scroll down to What happens when you take a payment?):
If you have additional questions or clarifications concerning the payments, please let me know. Any extra information will ensure a timely solution.