Im 20 years old and have been having a lot of pain in my breasts, my left one in particular. Although it does get worse when I’m on my period it always seems to hurt. This has only been hurting the past couple of months. I’ve been sexually active with the same person for years and do not use protection, I have periods each month and have done a test to be sure I’m not pregnant (came back as negative).

My left breast seems to have grown A LOT but my right one hasn’t grown. My right breast also hurts but no where near as much as my left boob.

Has anyone had this or know what it might be?