If you said "I am going to see you" and she said "Yes, please do", it's not AFC.
You see, the trick "I have something to do, would you like to come along?" it's just that, one option. It's not a rule. Don't get caught in a mentality that you should always follow PUA tatics, the DJ Bible commandments, and all that. Do what it works to see the girl.
None is always 100% occupied. Sometimes we do have nothing else to do Saturday afternoon. Just make sure you give the girl the impression that you're choosing to be with her. If she says no, go for something like "ok, wall.e is coming to a teather near here, I am going to watch it, have you seen it? Did you see the trailer? Oh, remember those other Pixar movies?, etc..."
Heck, if you drive 50 miles just to see her, she might feel obligated to return the favor. You see, it all depends on the kind of woman. Some like to be chased, but just a little, don't go there, buy her ice-cream and drive away. Make her know that you came for her. And that you want the kiss/fvck/whatever.
Sometimes you err, sometimes you get it right. Just keep trying.