What to do? Still any hope?

So i met a pretty girl on a private study class... She was the first one introduced herself to me. She also asked my pin for BBM. At first i was normal and cool that she had to make first move to text or contact me via bbm... I didn't read it right away because i rarely use bbm... So i replied to her 4-5 days after her first text...

She's actually physically my type but i didn't get my hope high and actually quite confident with myself at that time... After i replied her, turned out we had an agreement to go to class together at the same time. I think that we had quite a chemistry built up... But then i asked quite daring question about her age out of curiosity... Turned out that she is 19 years old while i am 26 years old... She was surprised as me too. I thought that she is 21-22 years old because she looks so mature, she said that she tough i was 23 years old and i look younger. Well after that actually everything still looks normal. I teased her by putting my best picture as profile picture which she said handsome and i replied the same for her picture.

So i had met her total four times in person in three weeks. The rest via message/BBM. I know it still short but i begin to really like her and have high hope. I never ask her birthday or twitter. But then yesterday i got her twitter myself to find more information, i realized then that yesterday was her birthday! So maybe i made mistake that because i want to go out with her and make her day good... I can't tell her happy birthday etc because i don't want her to know that i stalk her twitter which clearly say that i have high interest to her. So i asked that if she want to go to the class that day, but she said she couldn't. I know the reason because it was her birthday but i kept quite. Then i asked her if she would go out with me that day because i was bore.... She suddenly didn't read that part at all until today on BBM... I really like this girl and after a lot of hope given to me , she made me feel that i lose her... I don't know whether that she make that love trick play or if i really lose her... So i am confuse right now...