How much breast milk?

Pam • 🤰#2 due 1/2022

My son is 5 weeks old and take 3.5 ounces 7 times a day. He wakes up every three hours throughout the day and night to eat. How will I know when he needs more milk? Is that an appropriate amount? He was 10 lbs 11 oz at his 1 month check up.