If you were working from several devices and aren't sure if you were signed out of your account OR if you suspect there is unauthorized access to your player account elsewhere you can log out all sessions.
In goplay.plaympe.com go to My Account.
Select the Account Information tab
Scroll down to the bottom of the page and click Cancel all sessions.
Once you click it, you and any other sessions in all versions of the Player will be signed out and require signing back in.