Profile2: How to understand if user has not an associated profile? I'm not able to understand what is the code I should use to verify if user has (or not) a profile (made by profile2 module) associated.

I use profile2_load_by_user($uid, "my-profile-name") and it always returns me a "Profile" object... also for users that has not that profile (for example users listed in /admin/people/noprofile).

I know I can test if some mandatory field is currently filled, but do you know what is the "formally correct" way to proceed?

Thanks
If you are doing profile2_load_by_user and profile object is showing, then its profile object has been created. If Profile object has not been created for a user, then its profile object will be empty, means its pid has still not been created.

You can check for the same, in your database, inside profile table.