Should I take my 2 month old to the ER if he have cold symptoms?

He started coughing and bein congested yesterday morning... But now I hear the mucous in his nose and chest... I bought a humidifier and tries to clear his nose... Buy the mucous in his chest an this rattling noise it makes when he breathes is really disturbing to me. He ddoesnt have a fever and doesn't seem like he's in any pain... And he isn't cryin no more than he usually cry.... Should I take him to the ER or just wait til Thursday for his doctors appointment