The worst thing to do is rush it, it doesnt matter how long it takes, its actuaaly better because you'll end up being good freinds aswell a couple and you'll know her better. Id wait for something to happen rather than bursting out your feelings.
Not always true, you could slip into the "friend only" category, that is bad, few can make a romantic leap once they've been shelved as a 'friend'.
You, my friend need to offer this situation to her, and probably worded as closely to this as you can.:
"Look, I can't think of any fancy way to say it, but you should really think about breaking it off with ___________ so that you and I can pay more attention to each other without complications. You and I get along really well, and to be honest, I can't explain how I feel when I'm around you, I just know that I want to be near you all the time. I find myself in class daydreaming about your _____________ and your smile and just the way you make me feel when you're around. I guess what I'm asking is, do you feel the same about me?"
Don't beat around the bush too much, get to the point and let her know in no uncertain terms you want more time with her. Women like guys that aren't afraid to say what they think.
I don't know how many times I've sat and played the wondering game, and only come to find out I blew it by not jumping soon enough, giving some other jerk a chance to move in.
Strike while the iron is hot.
You may not get this chance again.
What would you think if you found out she was waiting for you to say something and you never did, so she figured you weren't interested in that way, so she ends up staying with the dork she's with, or finding some other dork?
Good luck and don't be shy, she's probably going through the same thing you are and is just playing the same game. You'll be happier in the long run. IF she's not interested, you'll find out soon enough, but it will end the waiting game and the dancing around the issue.
go git 'er!