When I had this problem happen to me, my account was soon hijacked. I would look into where you spotify app is connected to as far as external websites. I used to use one called Soundiiz so I could migrate youtube playlists to spotify and vice versa, but doing this opens you up to hackers. You can check here: spotify.com/us/account/apps/
Also look into which devices spotify can play through, currently I only have home PC and my Firetv connected. Right before I was hijacked I saw that there were other devices attached to my account.