When to start pumping

Mary

FTM. Looking for advice on when to start pumping? I am exclusively breastfeeding, and my doctor said to pump to help with production but my pediatrician said no storing of milk until 3-4 weeks. Baby is 11 days old. I have been pumping here and there but barely getting any milk. Baby, however is gaining weight like a champ and doing awesome. Any advice would be appreciated, in trying to understand the process, and want to start storing ASAP to have as much milk stored as possible for when I go back to work. Thank you!!!