Hi there, thanks for getting in touch. That domain is listed as pending renewal or deletion with the registrar: http://whois.domaintools.com/adelynphotography.com
It is not registered via WordPress.com, what you have with us is a Domain Mapping upgrade as part of your Value Bundle. You need to make sure that you are the domain owner and that the domain registration is current, then use the instructions for mapping an existing domain.
Alternatively, you can register a new domain that's not taken yet: Register a New Domain.