When babies latch on properly, some moms feel a few moments of discomfort at the very beginning of a nursing session. After that, discomfort should ease. You may feel a gentle tug on your breasts while your baby feeds, but it shouldn’t hurt.
If you feel discomfort during nursing, stop nursing and reposition your baby to get a better latch. Your nipple areola (the ring around the nipple) should be mostly in your baby’s mouth. When babies are latched on wrong, it can hurt or feel like a pinch each time your baby sucks. Over time, this can lead to painful, sore, cracked nipples.
If you have pain during breastfeeding, talk to your doctor or lactation consultant to make sure your baby is properly latched or that something else isn’t going on.
Source: https://kidshealth.org/en/parents/breastfeed-discomfort.html
