This means exactly what it says, that your email address has already been used to register an account in our database. So either you didn’t realize that your registration was successful or someone else used your email address. Either way, you should head to the log in page and try to access the site using your typical credentials. If that doesn’t work, then use the “Lost Password” functionality to create a new password. If you aren’t sure how to do this, check out the FAQ on lost passwords in the “My Account” section.