Everyone experiences different symptoms before menstruation. Some people experience breast swelling and soon after, their period begins, while for others, breast swelling can last for about two weeks or more before menstruation occurs. This varies from person to person because breast swelling is related to many factors. For example, some start experiencing it after ovulation, while for others, it might be related to staying up late and recent high stress levels. Some individuals may have mammary gland hyperplasia and should regularly have breast examinations, such as breast palpation and breast ultrasound, among other tests. Not every symptom indicates that menstruation will occur; some could be early signs of pregnancy. If the period is delayed, it is still necessary to check.