My son is 5 weeks old. For the past few days when I drop him off at my parent's during the day so I can work he has only been eating 6-7 oz of expressed milk. Today he has only had 2 oz from between 8am-1pm We were together yesterday and he nursed normally throughout the day. Is it normal for a baby to eat a lot less when away from their mother or should I be concerned? He does have thrush though so maybe it is due to that?