Some breast pain before your period is perfectly normal. Hormonal fluctuations cause changes in the breast ducts and the breast lobules. The lobules are the milk-producing tissues of the breast. Each breast has about fifteen to twenty lobes that branch into smaller lobules and each lobule and each lobule ends in a bulb. Milk originates in the bulbs and is carried by ducts to the nipple.

The boob pain usually starts during the second half of the menstrual cycle. When estrogen production increases and peaks just prior to the middle of your cycle, it causes enlargement of the breast ducts. Then, right before your period, another hormone (progesterone) peaks and causes growth of the breast lobules. These increases in size lead to pain.

Premenstrual breast pain can be mild or severe. Pain is usually less acute in women who are taking birth control pills. Some women find that caffeine intake can increase breast pain during pain. Also avoid very aggressive teenage boys who want to feel you up, but haven’t yet learned the correct method.