If you are still seeing the message to upgrade, or not seeing the PRO features. Make sure that you are logged in. Look for the "Sign In" link on the top center of the home page.
If you are already logged in, it is probably that you are logged into the wrong account. Most commonly, users sign up originally with a Facebook, Twitter, or Google ID and then later forget this is how they connected and create another account.
Did you sign up with Facebook, Twitter or Google originally? Make sure you sign in again with whatever ID you used originally.
If you can't remember you can use this form to lookup your username.