So there is signaling at birth that happens with a lot of hormones that are there for the mother, that the milk starts to be still at a level that is less because there is a connection that the baby needs to make and the baby still needs to learn to use its oral senses, the oral senses, the mouth senses for the baby to actually attach with the mother and become comfortable with that process of attachment and sleep and feed cycle, which till such time nature is so beautiful that it allows the quantity to be less than the need for the baby’s also left.
For the first few days and process after that, when the progesterone completely leaves the mother’s body to a level that becomes normal. Your other hormones that are supporting the lactation starts to increase when the mother’s milk starts to become much more and transitions into mature milk.