No matter who you are or what age you may be, when you're pregnant, your body is going to go through a lot of changes. And one of the most uncomfortable adjustments you may encounter will involve breast tenderness. Here's some more information on pregnancies and breast tenderness.
Breast soreness usually develops somewhere between the fourth and sixth week of pregnancy. It will typically subside somewhere into the second trimester. However, some women do experience a certain amount of tenderness through the entirety of pregnancy and breastfeeding.
During pregnancy, your body will undergo certain hormonal changes in preparation for birth and breastfeeding. As you get further along the pregnancy, the tissues of the breasts will ready themselves for the production of colostrum and milk. While your body may not start the actual creation of milk until you've given birth, the glands are triggered at this time, and may well start producing colostrum (typically, the earliest this will happen is in the second trimester). That being said, your breasts could still swell and feel sore.
During the eight week of pregnancy, the tenderness will usually be accompanied by an increase in the size of your breasts, unless, of course, you experience this growth at the very first sign of soreness, as some women do. As the size of your breasts increase, you'll not only feel a sensitivity to the touch, but you may also experience an itchiness. This is due in a large part to the skin as it stretches. If you have any concerns, speak to your physician.
After you've passed the first trimester, you'll most likely find that the soreness has almost completely waned. Sometimes it is replaced by a bit of leakage as the body usually begins to produce colostrum, the very first food a baby will eat, somewhere in the third month of pregnancy. While the soreness may have dispersed, it doesn't mean that your breasts will stop growing, so you may still encounter a little itchiness until you give birth.
Until this soreness subsides, you may want to think about getting a couple of bras that are specific to pregnancy, namely a good "nighttime" bra. This style of bra is fashioned expressly for sleeping while pregnant. It's made of a fairly soft cotton that doesn't pinch or restrict the area. These bras can usually be found in a maternity store.