Water retention is often associated with breast tenderness. Further discomfort may come in the form of benign lumps, which enlarge as the time of menses approaches and shrink following menses. This type of discomfort may increase in menopausal years, or conversely may diminish, bringing relief from chronically tender nipples and breasts.31 

Progesterone: In his practice of over 25 years, Dr. John Lee found that in many of his patients fibrocystic breasts were most often a sign of relatively high estrogen and low progesterone levels. He also found that "using natural progesterone routinely resolves the problem." He also found that 600 IU of vitamin E at bedtime, as well as 300 mg of magnesium and 50 mg of vitamin B6 a day routinely resolved fibrocystic breasts. He says "once the cysts have cleared up, you can reduce the progesterone dose to find the smallest dose that is still effective each month and continue the treatment as needed through menopause. This treatment is simple, safe, inexpensive, successful and natural."

Source: http://www.project-aware.org