For some reason your sign up has been flaged for review by a real person. Becuase DH has been recieving a number of fake sign-ups you’ll have to wait untill somone has time to look over your order and approve it.
As soon as they approve your account the domain registration should go through. I’d wait till tomorrow and see if it has gone through by then, but if you are in a hurry you could contact support and ask for a status update on it. Just log into the panel with the user/pass you created and click Support > Contact support and fill that out.