I had a huge lump in my left breast for a couple of weeks, I went to the doctor and she had me come in once a weeks for like a month, never did a mammogram, and said I just had fibrocystic breast. And it went away for a while and only showed up before my menstrual cycle. I haven't seen it in my left breast for awhile, but now there it a huge lump in my right breast about the same size as the left one. I would just really love a solid answer, If it helps i'm only 18.