Left eye

My two week old had a cough and some congestion last week that he caught from big sister. Took him to the doctor and they said to just use saline drops, no biggie. Now this week for about 5 days now his left eye has been FULL of greenish yellowish sticky mucus that crusts across the whole eye until he can’t even open it. The eyeball itself isn’t red and it’s only the left eye. I called the doctor yesterday but they haven’t returned my call. Any suggestions other than warm compress? Would this be from the cold last week or a blocked tear duct? :(