hey people, I have smoking for 3-4 years and since september, i have been coughing up blak stuff in my mucus, not evertime, but maybe...4-5 times a week, and only twice has it come out my nose when i blow it. i have to be checked for TB soon, or it could just be tar. does anyone have this problem or know anyone with it? I can't find anything through research, only forums about this topic, but they are all very recent, please help me if you can. thanks.