Can you have sore enlarged breasts and not be pregnant? if so what are the other possibilities?

PMS symptoms: Your breasts will respond to hormone stimulation during your menstrual cycle. If you have irregular periods you are more likely to have swelling and tenderness in the breasts. The onset of pregnancy is a large hormone influence on the breasts. The best thing to do is to see your doctor and have all of these possibilities evaluated.

Yes part of cycle: Estrogen levels peak mid cycle causing breast duct enlargement whereas Progesterone peaks just prior to menstruation and is associated with lobular growth. This will vary from one woman to another and can be related to family history/caffeine/weight. If atypical for you consider pregnancy test. Birth control may help to ease. See:http://www.Nlm.Nih.Gov/medlineplus/ency/article/003153.Htm.