Why did Jacob believe Bella had died after renesmee's violent birth?

Bella Swan gave birth to Renesmee by: ok, first Bella and Edward went on their honey moon and Bella got pregnant. Since the baby is haf-human and half-vampire, the baby could talk inside the womb. Renesmee said something like '' Get me out! I can't breathe in here!'' Then, Renesmee rips open Bella's stomach from the inside and she got out. But, blood was everywhere so in order to save Bella's life, Edward had to turn her into a vampire. I read ALL the books and it was AWESOOOOME! eNJOY! ;)