Does this girl like me and what should I do?

There is this girl I have liked since the beginning of the school year. I like her a lot because she is completely my type and she is very attractive. I have always talked to her and somewhat flirted with her. But I wouldn't really consider a friend, just someone I want to be boyfriend/ girlfriend with. If i didn't have that kind of crush I would still be friends with her. I always talk to her when my friends and her friends who are all in the same click or gang or whatever sit down on the steps to the up stairs and one time I whipped out some Skittles and she immeadiately scooted down next me and said "your my bestfriend now" and I gave her like half the bag. She sometimes pushes me slightly as a joke from behind when walking down the hall and I do that back to her sometimes. So anyway I have been working my way up to asking her out and since my school has a open campus I thought I would do something extremely casual so I would ask her to go to Safeway (which is where everyone goes) so I was going to ask her so I walked up to her and her cousin and I was going to ask he but she asked me to go with her first. We kind of walked together by ourselves even though she has friends walking at the same time. My friend (who is a ) ended up telling her that I told him that I was going to ask her out and somehow the math teacher in that cl knew (WTF) and he asked her if she was going to say yes and I think she was under a **** load of pressure in the cl so she said no. She doesn't have a boyfriend and she is the kind of girl to have long relationships. I was going to ask her out before the day got out but she was in the middle of speed walking to the bathroom, and my mom was picking early for an appointment. I try to ask her about what happened in that cl and she said nothing and then walked into the bathroom. I dont think she was trying to escape me but she tried to make the answer short cause she had to go to the bathroom badly. I haven't texted her or any thing this weekend because this all happened on Friday. I really like her and I kind of feel like if I lost her as one of my options as a girlfriend then I wouldn't even want to date the rest of the year. PLEASE give me an ysis on my situation! I will love you to death if you help me out! Also what should I do when school starts on monday? I have 1 hour lunches because it's finals week. Should I ask her to go with me to Safeway and kind of make it a somewhat regular thing and then work it up to a movie? and then the status of a couple?? PLEASE HELP ME!!! I need help espeacially if it is advice from a girl!! I am a very nice and compionate guy, I just hate it because I am bad at flirting and get a little nervous. HELP!!!