In the beginning, you will know your newborn is getting enough breast milk if he stops passing thick black or dark-green stools, which usually happens within the first five days. If he poops two or more times a day and it is yellow, seedy, and runny… hooray, everything is going according to plan!
During the first month, your baby will wet about six diapers and probably have three to four bowel movements a day. Once your milk supply is established, he should gain about 0.6 to 1.4 kg (21 to 49 oz) during his first three months.
If your baby is not gaining enough weight, this could be a sign that your milk supply is low. If you are concerned about not producing enough breast milk, speak to your health care professional.