What Is The Gray Green Discharge From A Duct That Is Swollen? Fear Breast Cancer?

Hi. I am a 24 yr old female. I found two hard lumps in my right breast, along with swollen milk ducts three months ago. I am not breastfeeding , nor am I pregnant. My only child is three years old, never breastfed. My maternal grandmother died of breast cancer at the age of 54. I went to my doctor, who gave me a referral for an ultrasound , due to the lumps being palpable. My doctor explained that she thought they were simply fibroadenomas, but that she was not completely sure. I went for my ultrasound two weeks after. The results came back normal. I was then referred to a breast specialist, as my doctor wanted to verify that there were no other tests needed. I was cleared by the specialist, breast exam normal. I was told by the specialist that she believed my milk ducts became clogged, and that it was nothing to worry about. Since then, my milk ducts have became clogged quite a few times. I can actually squeeze them, and sometimes they will pop, feeling like a water balloon bursting inside my breast. A week ago, I barely brushed against my left nipple , and had a watery greyish-green discharge come from one duct. It lasted about 3 days, only when stimulated. My ducts are swollen again, to the point that my breast feels heavier than the other. My nipple is extremely sensitive, and becomes errect without stimulation. I have tried warm compresses and began takin aleve for the pain. The pain is radiating from my nipple throughout my entire left breast. There are times when I have to just hold my breast due to the constant pain. I do not have nipple retraction, nor do I have an orange peel look, yet.