Girl has me confused?

I have a crush on this girl at the gym we somewhat know each other I've introduced myself and everything I'm interested in getting to know her but she has me confused sometimes she gives me a quick smile and hey, other times we'll have a conversation and other times she acts like I don't exist at the gym I'm pretty sure it's obvious to her that I like her, but I don't want to look like a fool and say something I might regret so does anybody have any ideas on how I should approach this?