Touring a developing country & 1.5 weeks ago, i came down with a very bad cough & thick green mucus. doctor wrote 3 days of amox. i felt better for a bit, but now i have same symptoms. a new doctor gave me 5 days of amox. should i worry of resistance?

Almost certainly was a virus as not better on antibiotics. Were you tested for COVID and flu. They do not respond to antibiotics. Go to CDC and they have info in drug resistance to antibiotics around the world. Would have been helpful to say where you were. UCLA has an International Travel medicine group and you can contact them but better to see Dr who knows you.

The bacteria rarely develop resistance after 3 day treatment. You should only worry if the amoxicillin is strong enough for the organism in the first place. Your new doctor probably prescribed augmentin (amoxicillin/clavulanate), not amoxicillin alone because amoxicillin is not strong enough when used for pulmonary infection unless amoxicillin was given as a reassurance rather than true therapy.