I have great chemistry with a girl at college and asked her out about two months ago. She said yes, and was talking to her on facebook when she cancelled. I said, I hope this isn't a rejection and she replied "no rejection, we're just friends + I'm seeing someone at the mo."
I've been seeing her consistently as I valued her as a person above all else and her facebook status has been single since I asked her out. The chemistry remains great if not stronger.
Perhaps now is the time to ask her out again?