Go to the ER, they'll check the goo you cough up, might culture it to see what kind of pneumonia you have, then they'll give you some antibiotics probably. They'll also probably x-ray your chest just to see how bad things could be.

If you let it go too long, they'll end up hospitalizing you, and you dont want that to happen. Much easier to recover at home, dont you think?

So go, have a doctor check you out, and when you're really sick, it's amazing how easy it is to show up at the doctor's office wearing your jammies, having not taken a shower in a week, or combing your hair...and not caring that people think you look like a homeless person. At least the last time I did that, I changed into clean pajamas just so I would be slightly less offensive.