Why do I still have yellow mucus, sore throat and productive cough 2 weeks after given amoxicillin for strep throat?

Stept throat. The most likely thing is that you did not have strept throat unless a culture was done. It is was a strept throat You probably have a viral problem that takes bout 2-3 weeks to get better if you take antibiotics or 13-21 days if you don't. Have others at your work/school had similar problems? Good discussion at Wikipedia for more info. Amox is not drug of choice in US.