Pumping to increase Milk

Carissa🐧 • 👨‍👩‍👧‍👦 💙💗 Married with a little boy and girl!
My doctor wants me to pump each morning since you have the most I guess. But by 2 I feel like I can't fill up so I don't do it ( my son has been sleeping for 20 mins a few times a day and wakes up hungry) can I build my supply even if I pump at night? I already leak a lot at night too