hi Im 34 yrs old just want to ask what is the usual cause of yellowish nipple discharge on one breast, spontaneous and uniduct on my right breast, I have it for almost 3 yrs on and off I usually noticed during my period before and after my period. I do have mammogram, ultrasound and nipple smear last june 2011 and its all turned normal, then I still saw it when I put tissue on my bra their a small tinystain like golden yellow and its hard when its dry on the tissue, its something like water but when I scrub my finger its a little bit sticky, this last feb. 2013 I went to my GP bec. of a discharge again and she did a breast exam she said there's a palpable mobile lump on outer quadrant where the discharge is located, she recommend me to a breast surgeon and mammogram. The result is normal again no need for ultrasound and surgeon said he did not feel anything wrong with my breast everything look normal, But still I Have a discharge and I do believe that there is something wrong with the duct, now I dont have a family dr I dont know what to do now is this a big concern? please help me I need an advice to an expert. thanks in advance