I have a sinus infection - should i go to the doctor or just let it run its course?

Give it time first: Normally a sinus infection has discolored drainage but clear drainage is also possible. An infection depends on the symptoms over time. Viral and bacterial symptoms are very similar. Even most bacterial infections clear without antibiotics. Consider antibiotics if symptoms worsening after 10-14 days, or persist more than 3-4 weeks. Most virus all infections clear after 10-14 days.Treat symptoms.