What made the term "secretary" offensive or un-PC?

I work for a real estate company. I answer phones, make copies, file paperwork, and type information into various databases. I am a secretary and that’s what I call myself when people ask about my job. I don’t find it offensive as a job title at all. It’s just what I do. There are many many worse jobs in the world, so I don’t really see the need to try to glamorize mine.