Usually. Roughly 50% of women have some discernable difference in the size and/or shape of each of their breasts. Even a difference of two entire cup sizes does not necessarily indicate a medical problem. Also, it is very common for the size, shape and color of breasts to change during a woman’s life, especially during or after times of hormonal changes, such as puberty, pregnancy and menopause. If you experience sudden or dramatic changes in the appearance of your breasts during a time that is not accompanied by hormone changes, or if you suspect a problem, you should consult with a gynecologist.