Facebook/history confusion...?

[♥Innocence♥]

Ok I'm rlly confused. I was browsing my history, until I saw a facebook link/line where it said '______ has messaged you.' You know like when you start talking to someone, that person having messaged you saves in you history. Problem is, I did not talk to this person. He is not even on my friend's list anymore (he's my ex). We haven't talked for months 3 months. I went through my fb msgs checking to see if maybe I received a msg and didn't see it, but there was nothing. I did not talk to my ex and my history is telling me I have... o.O Why was that invalid/untrue notification there in the history?
access to my account? O_O