Paypal's authentication sometimes creates a second "Authorisation" payment. This may look like a pending payment on your bank account's transaction history.
Don't worry - authorisation payments will automatically clear within 5-10 business days, and they'll disappear from your transaction history completely.
In the unlikely event that the pending payment doesn't clear within 5-10 days, please contact Paypal directly to resolve any concerns.
You can always login to your Paypal account here to view your transaction history.