Hi, my name is Hannin. I smoke and iv smoked other kinds of drugs to but only a few times. I'm 15, iv been smoking since I was 13. Anyways now when I spit the yellow stuff from my throat, it's not yellow, it's like yellowish black. But not everytime I spit its only maybe twice a day this happens to me... And sometimes it doesn't happen at all, but I'm worried, does this mean I have cancer?