Yeah, those always suck. Especially when you see the girl repeatedly in class... bit of a constant reminder.
The good news is, there are plenty more to come (both girls than end up crossing their arms and shutting down, and girls you snap up before that can happen).
And yeah, it does sound like auto-rejection - she wanted you before, but it didn't happen fast enough. Take the lesson from it (move faster next time) and use it with the next girl.