How to tell if your getting played?

A girl and I we have been seeing each other for about a month now. I feel like we have good chemistry, and I really like her. She seems like a good girl but she has a hint of a dark past. Some times it just seems like things are too good to be true. I have a fear that I might be getting played, but I have no reason to believe this. Maybe I'm just insecure. How can I tell if i'm getting played? P.S. this is my first relationship