A few days ago, I met this girl from a friend's birthday bash. Actually, she is a friend of my girlfriend's friend. We were introduced to each other and had a really good conversation. We then exchanged numbers and I was hoping to hook up with her after our first meeting. I called her a day after the party. She did not respond to my calls I was wondering why. I waited for 2 days and yet, there was no return call. What should I do? Do I have to be persistent in calling her or just wait?Until when?