It is normal for a mother’s breasts to begin to feel less full, soft, even empty, after the first 6-12 weeks.
Many mothers have concerns about milk supply after the early weeks because they notice a drop in pumped amounts or they notice that their breasts feel “soft” or “empty”. It is normal for your breasts to feel mostly soft after the first weeks, although if there has been a long stretch without nursing or pumping they might feel a little full and heavy.
The feeling of fullness (sometimes even engorgement) that nursing mothers notice during the early weeks of breastfeeding is really not the norm at all, but means that mom’s breasts haven’t yet adjusted to the amount of milk that baby needs. At some point, typically around 6-12 weeks (if a mom has oversupply it may take longer), your milk supply will begin to regulate and your breasts will begin to feel less full, soft, or even empty. You may stop leaking, you may stop feeling let-down (or feel it less), and if you pump you may notice that you’re not getting as much milk. This doesn’t mean that milk supply has dropped, but that your body has figured out how much milk is being removed from the breast and is no longer making too much. This change may come about gradually or seem rather sudden. Many people are not aware that these breast changes are normal because so many mothers stop breastfeeding early on and never see this change (or mistakenly interpret this change as a sign that milk supply has dried up and wean because of this change).
Why the change? Although milk synthesis has already switched over to autocrine control (driven by breast emptying) after mom’s milk comes in, the extra hormonal influence of the early weeks and months frequently causes moms to have more milk than their baby needs. Early postpartum hormonal levels tend to “turn up the volume” on milk synthesis so that extra milk can be produced if it is needed (most moms can produce enough milk for twins or even triplets). Over the first few months, this high baseline prolactin level that is the norm in the early weeks gradually decreases to the lower baseline that is the norm for later lactation. After this point it may be easier for mom’s body to adjust milk production down to baby’s needs.