What is milk "coming in"? This information is available and taken from Baby Buddy app, verified by experts in our Editorial Board including representatives from Royal College of Midwives, Royal College of Paediatrics and Child Health and Royal College of Psychiatrists as well as other key health organisations in the UK. To download Baby Buddy, visit the relevant app store of your choice: For the first few days after birth your breasts make colostrum (thick and yellow, like a banana milkshake) for your baby. Then your regular milk arrives in your breasts - this is called your milk "coming in". At first your breasts don't know how much to make, so they make loads and they get enormous. Once they work out how much your baby drinks, they'll make exactly the right amount so you won't feel "full" all the time. If your breasts feel sore, hard or warm when your regular milk comes in, that's normal. It will only last a few days. You can make yourself more comfortable by feeding your baby often, and making sure he's in a good position for feeding. Taking a warm shower or bath may make some milk leak out by itself so you don't feel so tight. And some people swear by putting cabbage leaves that are chilled from the fridge or freezer in your bra. (Honestly - we're not making this up. But you have to wonder who discovered that!) You can also take paracetamol if your breasts feel painful. And don't wear an underwired bra - a soft bra with the straps tightened will give you the most comfortable support. To find out about some common problems with breastfeeding, watch the video.