How do i know if i've had pneumonia or severe bronchitis?

i have taken 3 rounds of z-packs in the last 6 weeks for uri's. this last incident almost did me in. i had just finished a cruise in the caribbean, landed in puerto rico, flew to the u.s., and by the time i got home, was sick as a dog, fever, chills, hearing a crackling sound in lungs, etc. my dr. called in a z-pack, just finished it today and am still really tired and weak, but feeling a little better. i was so sick the last week that i thought about going to the e.r. is it important at this point to know whether i've been fighting pneumonia or just the flu? i start back to work tomorrow and am still just really, really tired. just want to sleep. should i just listen to my body now or go get a chest x-ray to see if i've had any damage?