number of ounces of breastmilk for 3 week old

Cindy
Hi all! My baby is 3 1/2 weeks old and he's weighing in at 7 lbs. How many ounces of bottled breastmilk should I feed him? I've been giving him 2 ounces, rarely 3 ounces around every 2-3 hours. Just want to make sure he's properly gaining weight! Thanks!