When you have a self-installed WordPress.org website/blog, it can get Site Stats using the JetPack plugin when connected via WordPress.com . But, how do you know which wordpress.com account your website/blog is connected to via JetPack? Here’s the response I got from tech support:
While you cannot find any information about the WordPress.com account linked to your Jetpack site in your dashboard, this site will appear in your list of blogs on WordPress.com.
If you do not remember which account you used to make the original connection, the best solution is to go to the Jetpack menu in your dashboard, and disconnect from WordPress.com.
You can then reconnect with your current WordPress.com account… Once you have reconnected, your Stats, subscribers, and other Jetpack options will be reconnected to your site and associated to the right WordPress.com account.