My year in music showing someone else’s music (account hacked?)

[Alucardi]

I just recived my year in music and it is totally of. My top played song is a song I never heard before and it is a genre I never listens to, hip hop. In my top 100 song I had around half being hip hop or r n’ b, I never heard any of em before. They where also in my library I saw now, the plus sign had changed to a green checker thing. I never really use my library so I never noticed the songs until now. 

How can this be? Was my account hacked at one point? Can I check my login history somehow or what units have used my account? I am the only user of this account and I only have it on my 2 laptops and my 2 iPhones.