Hi. I have a selection of motherease airflow wraps that I have picked up preloved, but only have one in a size XS - will small airfolw wraps fit a newborn or should I look for some others for the first few weeks? Know this is a 'how long is a piece of string' question as newborns come in all shapes and sizes, but want to be able to use reuseables as soon as possible once the baby is here. Thanks!