My son is having cough n throat infection from 3days, consulted doctor he gave antibiotic mega cv 228.5mg and ambrodil plus syrup n doloper 250 but after using these medicines from 3days also only cold n fever has gone but still there is cough continuously, even after giving antibiotics for 3days there is no improvement in cough why, n still there is another bottle of antibiotic left, should i continue the medicine for few more days n see or consult the doctor again. is this viral infection or bacterial infection.