Should I be worried about nipple discharge?

When should I seriously worry about nipple discharge? I turned 20 this week but when I was just about 19 I noticed that if I squeeze my left nipple, a sticky fluid comes out of only 2 ducts. Not a ton of liquid comes out: maybe a few droplets and after a couple a squeezes it goes "dry" (nothing more comes out). What worries me is that it's only from one breast and only from two ducts, plus each duct produces a different color. One is a light yellow-y green but the other is a very dark, almost brown green both sticky. I don't have insurance so I've been putting off getting checked for a bit over a year now, are these signs of something more/bad? Thanks!