I've posted this before but the advice bears repeating. You're over thinking this. There are only two possible outcomes here. Ask her out and she says either yes, or no, and anything other than yes is no. Maybe, later, try again next week, I have to wash my hair all = no. No matter how much you think about it, how much you roll the possibilities around in your head, no matter how much you think about what type of person she sees you as, there are still only two possibilities, yes and no.
I think a lot of you guys are deathly afraid of rejection, as if it's the end of the world. It's not believe me. You're going to get rejected much more than accepted in life, that's just how it works, especially when it comes to dating. I was the same in my teen years but I bit the bullet and did what I had to do. My best weapon in this fight was humour. I would often be prepared for rejection with humour to cover up my disappointment, but also to make them think they may have made a mistake by not going out with me. Even my approach was humourous most of the time. "Hey, I was just curious, I'm in a period of self reflection and I asked my best buddy to give me three reasons why he wouldn't go out with me if he was a girl and his answers threw me for a loop. Can I ask you for three reasons why you wouldn't go out with me?" More often that not, she's immediately going to say, "I'd go out with you for sure". If she doesn't you'll learn a lot more about yourself, and her, than you ever will beating around the bush. Be creative, think outside the box. The worst thing that can happen is you are in the exact same position you are in now. The best is she says yes and off you go.