When I developed pneumonia the only symptoms I had were a nagging cough and a little pain in my right shoulder blade when I coughed.
The fact that you’re still coughing up yellowish brownish stuff three weeks later is the clue that whatever you had then has not been cleared from your system. Just because you feel ok otherwise doesn’t mean there isn’t an infection hiding out deeper down.
The main reason why the initial cold makes us feel so crappy is because it involves the nose eyes and sinuses.
Once the infection moves deeper into the chest the nose and eyes aren’t involved as much.
But just call your Docs office and describe accurately the color of mucus and the fact that you have a persistent cough for the past three weeks. See what they have to say about it.
As I said, i’ve been through the same thing more times than I can count.
Your Doc will be able to tell in two seconds flat after listening with the stethoscope. I’ll be flat out amazed if all he does is just tell you not to worry about it.