Just need to get this out.

I’m 21 years old and scared today I noticed that if I squeeze my left breast there is a clear yellowish discharge that comes out. Not much at all a very little bit. It’s only out of my left and I’m not pregnant (at least if I am every pregnancy test I’ve taken is wrong and my periods are still just as strong and as long as they always have been.) My family has a VERY strong history of cancer. I don’t feel any lumps, my breast isn’t sore and it’s not swollen or red. Does anyone know of any reason for discharge other than cancer and pregnancy. As I said it only comes out if I squeeze hard.