Michael1 is joking, by the way.
I like the poster who said 'keeping a cool ahead and you're set (sic)'.
Yeah, it sounds like you're doing all right man. I mean, by your own admission it was when you 'tried for smooth' and instead of just typical that you got an atypical response, right? Maybe you did this because you felt that that was A MOMENT to try and be more suave. Or that you've not had many encounters like this before (no biggee and not as uncommon as you'd otherwise think).
I guess there are two ways of playing it. You can either try and brush it off. If you were doing it that way than I'd say maybe don't try TOO HARD to get her attention. If she's liking you then she'll figure it out. This may sound odd but in reality the LESS attention you give girls, or the more you make them wait, the more they try.
I agree with other posters saying that you should wait. Don't respond in a greater amount unless you really feel its the RIGHT THING TO DO; otherwise more often than not, especially for something that's in a gray area or just starting out, you'll come off as more aggressive than what was otherwise the tone before.
Otherwise, you can address the issue straight out. I would NOT apologize. That's something that makes you seem supplicating. You could just, for instance, thank her for her thoughtfulnss in checking in how you were. A compliment that could follow this might be that you felt it made some of your symptoms ease/made it easier for you overall.
Overall, sir, just remember that these things aren't ever straightforward for ANY of us. Gosling's character in that film 'Crazy Stupid Love' is an exaggeration on many fronts. But just remember there that once he develops more than attraction into actual feelings for the costar, he stumbles. Its because, film example aside, as much as guys are wanting to PURSUE, girls are more often than not flighty and unsure of themselves. It turns into a game, kind of.
For now, just do your coping strategies. Maybe google 'Social SA' Strats. You can rehearse how things go should your schedules not align. Maybe pursue some other females - just small things like reconnecting with a female friend via facebook or responding to a more romantic Craigslist ad - so as to take the pressure off this one chick... And that, finally, is probably the biggest thing that's going on here. You've had a lot of forward action by her and you're worried that because of your comment its all going to crash to a halt.
It won't. But at the same time you still can **** up, but if not now, you can take the time you'd of otherwise spent with her to work on yourself so that when this does arise again (attraction seldom loses its flame no matter the time elapsed) you're more versed with these dynamics/situations!
A little long. Let me know if I made any sense please =)!