I Need Help With PayPal Please Help? 10Pts?

Ebay is supposed to give me refund and they told me i gotta sign up for paypal. but i put my checking account number, but i dont know if i put in my correct number or not. i have a feeling maybe i made a typo. what should i do or is there any way to double check what i put for my checking number? i did it by going to my account and then clicking on bank account.