My period is a few days late . my breast are feeling heavy and im not sexually active?

Some thoughts...: In a woman with regular periods, some causes of a late period include: excessive weight loss or weight gain, increased exercising, emotional stress, having an illness, traveling, medicines (like birth control pills), hormonal imbalances, etc… Seeing her Ob-Gyn doctor is a good idea if symptoms are persistent, recurring, or worrisome.