So my ex girlfriend broke up with me on friday but texted me on sunday -what should i do..?

well when she texted me i took my time to reply..and she been texting me ever since,...and is now speaking to me on facebook but i aint replying back..- i know i have to act like i dont care and all....so they can chase u and all but i was wondering when do i stop all this...like i do want her back but people saying let her wait let her chase u blah blah...and i just want to know...the time length and what kind of stuff should i text..should i act caring...i dont know..like --i dnt see why people would keep talking to you if your acting uncaring to them.so why do people say act like you've moved on..im confused please explain..thanks in advance