Anyone use my Netflix account without permission?

I recently got Netflix for me. But for 5 days I was shown the series were viewed that I never looked at me. Dan I also got an email that a device has logged in Hessen. But I live in Bavaria. The access data has only one other person no one else. Can I somehow lock this person and also see the exact location and if so. I have an established profile and the other person has my own. Everything was looked over my profile which I did not look at.

How about changing your password?