Actually, Daisy does call Nick in Chapter 7. First, Gatsby calls for Daisy, inviting Nick to Daisy's house the next day for lunch. He mentions that Jordan Baker will be there. Thirty minutes later, Daisy calls Nick herself to confirm that he is coming. She seems relieved to hear that he will be there. Nick thinks, "Something was up." The idea of Daisy's inviting Gatsby to lunch at her and Tom's home, whether others attend or not, fills Nick with a sense of foreboding. It is in Chapter 9, after Gatsby's murder, that Nick waits for a call from Daisy that never comes.