Girlfriend gone cold and confuding me?

My girlfriend sometimes would go from hot to cold.

Like when we go to bet she usualy calls me pet names,and sends kisses and hearts,but some mornings she wont even text me goodmorning. This sometimes causes arguments,because she does this like 2 or 3 times a week. However i never get clingy and also act cold when she starts to act like this. Today she has gone cold again,a bare goodmorning, no kisses no sweet names mo nothing. I sent her also a plain goodmorning and respond pretty cold,and she tries to initiate conversation.