Julie is pregnant at the beginning of the whole story. After a whole year she should have had a baby (if she were alive and not dead after the accident). After Nick's time-travel (when Julie gets to live), there's no mention of the baby. However, during their argument after Nick got himself fired, Julie mentioned 'I can't forget what we lost in the accident', implying she possibly had a miscarriage due to the crash - hence why there's no baby even after a year.