Despite views to the contrary, breasts are never truly empty. Milk is actually produced nonstop—before, during, and after feedings—so there's no need to wait between feedings for your breasts to refill. In fact, a long gap between feedings actually signals your breasts to make less, not more, milk.
As milk is removed from your breasts, your body is signalled to make more milk. The more frequently and thoroughly the breasts are emptied (though breasts are never truly 'emptied'), the faster they try to refill.
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.
To put a number on it, it usually takes about 20 to 30 minutes after feeding to generate enough milk for your baby, and about 60 minutes to replenish fully. The more often your baby feeds, and the more they empty your breasts, the more milk your body will produce.
It's common for moms to have different amounts of milk-making tissue and different sized milk ducts in each breast, so one breast naturally produces more than the other.
You're not getting let down. If your breasts feel like they're full but you're not able to get the milk flowing out when you pump, it could be that you're not achieving let down. The let down reflex releases your milk from the milk ducts. This only occurs when you're either breastfeeding or pumping.
Generally, moms should be pumping every 3 hours. Pumping more often can help stimulate breasts to produce more milk. Moms can try pumping both breasts for 15 minutes every two hours for 48-72 hours. Then moms can return to their normal pumping routine. Pumping for longer than 30 minutes may not be beneficial.
How do I know whether my breasts are empty? There's no test or way to know for sure. In general, though, if you gently shake your breasts and they feel mostly soft and you don't feel the heaviness of milk sitting in them, you're probably fine.
Your breasts feel softer
This happens as your milk supply adjusts to your baby's needs. The initial breast fullness reduces in the first few weeks. At around 6 weeks, breast fullness is completely gone and your breasts may feel soft. This is completely normal and has no effect on your milk supply.
Your milk supply is considered low when there is not enough breast milk being produced to meet your baby's growth needs. Many mothers worry about their milk supply, especially in the early stages of breastfeeding.
If your baby's swallowing has slowed, they have started to fall asleep, and/or they seem frustrated at the breast, it's time to switch sides. Sometimes switching breasts multiple times per feeding can be useful, especially in cases of sleepy babies or low milk supply.
Some might feed every 90 minutes, whereas others might go 2–3 hours between feedings. Newborns should not go more than about 4 hours without feeding, even overnight.
It's important to remember that your baby is much more effective at getting milk from your breasts than a pump will ever be. A healthy, thriving baby will get more milk than you a capable of pumping.
Some mothers can store 4-5 ounces per breast, so baby would only need to eat from one at each feeding. Other moms can store 1-2 ounces and baby would need to feed from both breasts. Storage capacity is not indicated by breast size, but by glandular tissue in the breast.
Ultimately, if your baby has reached its birth weight and you're pumping enough milk during the day, it's okay to sleep eight hours without pumping at night. Keep in mind there is an adjustment period for your body as it begins to acclimate to the decrease in overnight milk removal.
Massage your breasts before you pump.
This causes a faster let-down and milk with more fat. Massaging your breasts near the end of the pumping session will ensure that you fully drain your breast of milk. It may also help you to make more milk, if you need to.
If you're pumping for a freezer stash or to store milk for a future separation from your baby, try pumping shortly after you finish nursing – maybe 15 to 30 minutes. That way, your body will have an hour and a half or so to replenish breast milk for your next nursing session.
Most moms will see their milk supply stabilize around the 12-week mark. It may come earlier or later (kind of like that due date!), but you should know what to expect from your milk supply around then. One of the fastest ways to increase milk supply is using your breast pump in between feeding sessions.
Something I recommend to moms is the 5-5-5 rule. Try and use milk within five hours at room temperature, five days in the fridge, and by five months in the freezer.
If the breasts do not get emptied completely or often enough, the body begins to produce less milk. Some mothers say the milk never stops flowing while they pump. Typically, you should not pump longer than 30 minutes, even if the milk is still flowing.
Increasing your milk supply will take time, so don't give up. Even dry pumps (when you pump but nothing comes out) sends a signal to your body that more milk is needed on tap, so it's getting the work done even if there's no output to show for it right away. Stick with it and you'll see the results after a few days.