Breastfeeding Fussyness

Hi all, i have a 2 week and 1/2 old baby and she started to be fussy when i feed her. I am exclusively breast feeding and i do have milk, i am lucky about that. What kind of worries me is that she wants to feed but when i put her on, she latches for few seconds then immediately releases the nipple and pushes me..and does that constantly. I dont know why is she doing that....if i take her completely off the breast she starts crying..anyone knows what is she doing/ wanting?