Needing some advice?

I work at a department store and one of my co-workers I thought she was a guy at first because her swag is like a guy, until we started talking and she told me her name. Anyways I thought I'd be turned of by the fact that she was a girl, but I don't know the way she talked and everything was just a major turn on, the only thing I'm worried about is that I don't want to start something that I may not want me and her are now friends and everything but I don't want to mess that up. But lately I can't get her off my mind, I've thought about us becoming a couple and being able to make-out and all that. The hard part for me is going down, because I don't like people to go down on me, and a lot of girls like that and I'm not ewwing it but it's just like after I did that I wouldn't want to kiss the person and after they did it I wouldn't want them to do it to me. Because I guess I'm thinking if your willing to go down on me how many other people have you gone down on. I mean so I don't know if this is really just a physical attraction because I find a lot of studs, or butch females attractive but I don't know if it's just because of the way they carry themselves or what. Do you think it's just a physical attraction, if I've had thought of being there girlfriend?