What is this weird taste in the back of my throat?

For the past few days, maybe 4, I've had this weird taste in the back of my throat. It comes and goes, so I don't notice it all day. I don't have a cold or anything else, it does kinda seem like its drainage though. Can't really describe the taste, but it doesn't go away when I eat or drink, or brush my teeth. Anyone ever experienced this before? I worry a lot, so this isn't helping. It couldn't be from like my brain or something could it? If it was, don't you think I'd have other symptoms?