Oh my goodness...this girl is just playing hard to get that's all, the fact that she said that you wanted to get into her pants means that she is just apprehensive that you will use her for sex like other guys especially since you moved too fast . It appears she is like me in the fact that she can be quite strong and can hold off her emotions to not call you in two weeks plus that was probably a test anyways to see if you would eventually call. I also think she might be a little scared and come to think of it she might like you which is why she is putting up all of these defenses. The fact that every time you ask her out she goes out with you means that she wants you to prove that you want her and are willing to pursue her and not just for sex. Of course time will tell just what her game is, but you cannot come on too strong otherwise she will run, you have to be patient and bide your time, focus on being her friend and not so much on the sex and she will come around, you have to earn her trust.
I am going through the same thing with a guy, i am used to the guy making all of the plans and i am too scared to call him and make plans because i am terrified of rejection so i wait for him to do it. And now its probably over because i am too chicken to pursue him to make plans and he is probably like "she is a headache" and not interested. I can't say that he doesn't know i am not interested because i got drunk one time and told him i was in love with him and we should get married, I woke up the next morning and was like what the hell. Anyway now its to the point where i think its over because he is stubborn and doesn't chase after women and i am stubborn and i refuse to chase after a guy or make plans because i feel like he is the guy and should take the lead. By the way quality women do not chase men, the crazy unstable ones chase men down, they have nothing to lose and all they see is opportunity and what they want.
So when you say because she does not call or make plans but says yes when you call her to do something doesn't always mean she is not interested, perhaps you should take the lead like a traditional guy and give her enough rope before you hang her. Just my two cents.