Breast cancer question?

I have been feeling very fatigue for the past 6 months and was wondering what it could be. I also havent gotten my period since then and took 3 pregnancy tests and am not pregnant. I am 19 and noticed my left boob is bigger than the other it also has a dent in the middle/side of my nipple. Some discharge comes out of both nipples and I also have like browinish dots inside my hair folicules on both breasts. They both feel lumpy but the left one feels like it has more ridges in it. I asked my doctor to do a breast exam a couple of years ago but she told me they were fine and didnt even look at them due to my age. Do you think I should ask again and this could be Cancer? Is a symptom of breast cancer no period?