Nipple Discharge

I've looked this up on WebMD (terrible idea btw) and it says I possibly have breast cancer, but: whenever I squeeze my nipples this kind of yellowish greenish discharge comes out of one and clear comes out of the other. It's been happening for years and my nipples get sore if I don't "express" them, so to speak. I know it's probably TMI but I'm worried. I haven't talked to my doctor about it yet because I'm scared that she might say it's the worst possible scenario. /: anyone else have this problem, or know what it is?