My daughter got several bouts of walking pneumonia. The cough may be dry at first, but will become "productive" and get bloody (at least, hers did--- the first time they called from school saying she was coughing up blood... OMG, was I scared!)
As for being worse at night... I am pretty sure that is common with everybody with even regular coughs. We lie there and and want to sleep, but the mucous just settles in there "tickling" at us to cough it up... over and over and over... ugh!!! And yes, regular coughs can linger for weeks and even months. And the reason we are so increasingly tired is that we not only are expending energy coughing, it is keeping us awake!!
I love the OTC cough medicine - Delsym ("Delete Symptoms") - for nighttime, but it doesn't work for my younger daughter. When we get tired of coughing and absolutely NEED SLEEP... and trials of various over-the-counter cough medicines, decongestants, antihistamines, and a week of nasal/sinus irrigation have not done the trick.... that's when it may be worth going to a doctor and getting prescription medication for the cough... even a regular cough... so we can SLEEP!