Surprised no-one's mentioned that it depends what sort of pneumonia it is.
If it's viral (as opposed to bacterial) pneumonia, it's nothing like so serious and antibiotics won't do anything to shift it either. If this is the case, then there's not much more you can do other than just rest and wait for it to clear up, which will probably be around a week or two and then you're back to work etc.
But that said, I have no idea how OP has self-diagnosed that they may have pneumonia in the first place, so agree with all the advice here that they should go and see a quack asap.