Sick baby :( what to do?

My son has been sick for about a week. I called his doctor and she said as long as he doesn't get a fever and continues to eat then he doesn't need to come in. All that he's had is a dry cough every once in while throughout the day and a really bad runny nose. I'm not sure if it's allergies or what. I've been giving him zarbees for his cough and suctioning his nose after using saline spray. But this runny nose is still really bad. I don't know what to do anymore. Does anyone have advice on a runny nose and a little cough? Thank you