I am currently battling a sinus infection and my doctor prescribed a nasal spray. Dr also wrote me a prescription for amoxicillin and said to take it if it seemed like the infection was progressing to a bacterial infection(discharge discoloured). Does this apply to nasal and chest discharge. I have only had clear nasal discharge so far, but I did hawk up greenish phlegm a couple of times. Should I be taking the amoxicillin?