Why do i experience breast pain 1 week before periods?

Throughout a woman's menstrual cycle, hormones fluctuate. At the time of ovulation, (about a week or so before your period) Estrogen increases dramatically. This additional estrogen signals your ovaries to release the egg, it also signals your breasts ducts to enlarge (thus causing tenderness). If the egg is not fertilized and implanted, then the estrogen drops and you get your period.

Breast soreness and swelling is a common symptom of premenstrual symptoms (PMS), which happen right before a woman’s period. It is likely caused by hormone changes in the body. (Other PMS symptoms include bloating, tiredness, and mood swings.)