I had pneumonia just over a year ago. I still have pains in my chest.
Seriously, if it was bacterial you really really need to take it slowly. Pneumonia attacks your lungs and your o2 absorption capacities are probably vastly reduced. My take is to focus less on aerobic workouts at the moment and more on anerobic to gain back some muscle, and give your body time to get the aerobic capacity back. It can take months
Dude, that sucks...no real suggestions from me as I'm getting over the exact same thing...came down with flu and then pneumonia...four weeks ago too...still weak and just trying to make it through the day. Good luck!