did i lose my chance with this girl or should i continue to do something?

[tiffonn]

I met her 2 months ago. Since then we have met 3 times and once talked on the phone for about 3 hours. So she left an great imperssion. I might even say that she may have been the most interesting girl i have ever met. We had chemistry and a lot of fun when we were hanging out(just hanging like friends). I have her on facebook, twitter and other internet places were we used to communicate.

It is like this - We used to reply on each others tweets and facebook. Also, she was the one who got my phone number(not from me) and called me that one time. I got her both(she usually doesnt give both her numbers to people) mobile phone numbers. The thing is that all the time she was the one starting the replies and texts and, about 2 weeks ago, she stopped replying and stuff. I had the number and i really didnt want to call until i felt it is right. I wanted to ask her on a date but she wrote on twitter that she was hanging with her best girfriend that night so i didnt even ask.
So....4 days ago she met one of my good friends. This dude is one of my best friends and he didnt and probably still doesnt have a clue that i even know the girl. And they have been haning out the past 2 days.
And i have this bad feeling that i might have missed my opportunity to have a relationship with her. Am i right? If i start to reply myself and find the guts to call her before they can start dating(if they do at all) will it change something? Should i, a month after getting her number, try to call her? What is the best thing for me to do?

P.S: SHE IS, HANDS DOWN, THE MOST AMAZING GIRL I HAVE EVR, EVER MET! IM NOT SHY, JUST I'M SCARED AS HELL, OF REJECTION EVEN THOUGH WE HAD SPARKS!!!