Went for the kiss and got a cheek. What do I do?

I (male) went to the movies with a girl from work. I am 16 and she is 17. We went to the movies, and about 2/3 of the way through I put my arm around her and she was cool with that. After the movie she seemed to avoid getting too close to me. She wasn't running away, just never came within about 6 inches. Before I got out of the car for the night, I went to give her a kiss and she turned so I got her cheek.

I feel like I missed a sign somewhere. We seemed comfortable with each other, and she was laughing a lot. I don't know if this means she isn't interested in dating me or if she just didn't want to kiss. I will see her at work tomorrow (start my shift at 5), what should I say/do?