5 Month Old..Cold?

Hello all! First let me say that yes, I will be making my bub an appointment with his pediatrician tomorrow! But just to help me get an idea, I just want to know what you all's opinion is on this. My 5 month old boy has been more fussy than usual, has a VERY slight runny nose (I mean so slight that we don't notice it), and a very plain cough: almost to the point that it sounds fake. He does not have wheezing, he does not have difficulty breathing, he is not running a fever, he has not lost his appetite at all, and he is still generally happy and energetic. I'm thinking just a normal cold? The temperature outside has dropped drastically in the last week where we live, and he has been outside a little more than usual this past 2 weeks. I also listened to a few Youtube videos of children with Whooping Cough and it sounds nothing like his, so I'm pretty positive that isn't it. Any ideas?