Need advice...what should i do??

so i have this friend and weve been amazing friends for a while now. i really started to like her the last few months and we talked on the phone once a week or so. i would call most of the time but she called a few times too. anywya, this is long distance so its hard but i still wanted to show her that i liked her. so on valentines i had a flower sent to her at work. she loved it and she told all her friends and bro about it before she even mentioned it to me. so lately when ive tried calling she doesnt answer or call back or txt. last sat. she called me back but we didnt talk long cuz she said she was super tired but she was on IM later that night pretty late. so that totally confused me. and then sometimes ill IM her and shell never reply...she might not be there but still she nver replies. so i just need a little advice. should i just quit trying to talk to her for a while? how long?? or should i try and talk to her about us?? any advice would be awesome!

Need advice...what should i do??
maybe you should back off for a while then start trying again cause if you show her you care and will wait how ever long it takes then maybe she will see how much you care for her...