b'your newborn babystummy is smallAt birth, a babys tummy is about the size of a toy marble.(1 to 2 teaspoons) At first, your baby will drink tiny amounts very often. The first milk you make for your baby is called colostrum. It is thick, yellow and full of the protein, vitamins and antibodies that protect your baby from getting sick. You will make small amounts of colostrum at first - just the right amount for your babys tiny tummy. Your milk supply changes around 2 to 5 days after birth. Your breasts may start to feeltender and full. The best way to prevent swollenbreasts is to breastfeed your baby often - at least 8 to 12 times By day 10, a babys in 24 hours.tummy grows to the size of a ping pong ball.(1 to 2 ounces)When you breastfeed often, your milk changes to meet your growing babys needs. meet your new baby 8'