I also began pumping after a day or two to get my milk in faster and stimulate more supply. (twiniversity.com)
I would definitely use what stored milk you have first and then begin pumping during the day to help build your storage. (justbreastfeeding.com)
Once the baby is a couple of weeks old and things settle down with the new routine, mom can begin pumping milk to save for her return to work. (omahabreastfeeding.com)