i've been smoking weed for about 3 years. within the past year or less i have been coughing up little globs of black flehm. it usually happens after i smoke, but sometimes it can go on and off for weeks when im not smoking. i have to exhale until i hear crackling in my lungs and then 'hock' it up into the sink. am i gonna die because of this? i know its not a good thing, but is it a bad thing?