Falling for a friend

A cliche, I know. XD

Well, recently I went out with someone I knew since back in grade school. It was more of a friendly date because I needed someone with me for some occasion.

Now, she is not really a 'friend' as in close friend, more like someone I've known for a long time, but get along with really well.

She's very attractive and one of the most popular girls back when we were in high school, while I'm sort of considered to be one of the geeks. I never really considered being in a relationship with her, since we belong to different social groups.

We ended up going to the same college and taking up the same course.

Everything feels great when I'm with her. I would always make her laugh and we'd always have fun. I'm thinking of making a move on her, but it might seem weird. It's only now that I'm having feelings for her like this and she might still see me as a friend.

What should I do?