It is normal to experience slight nipple pain during pregnancy. After pregnancy, due to the decrease of estrogen and increase of progesterone in the body, there will be a slight pain in the breast. Especially in the middle and late stages of pregnancy, the milk ducts will expand, leading to milk production, which is also normal. Only in such a case will there be sufficient milk after the birth of the baby. During pregnancy, if you have sore nipples, you should pay attention to see if there is any redness or swelling. If there is redness and swelling, it should be triggered by an inflammatory infection, and it is not a normal manifestation. You should try to pay attention to hygiene and cleaning to avoid bacterial infections that can lead to nipple pain.