Cough?

My 5 month old has been coughing but it sounds like a fake cough. I thought maybe he had a hair in his throat or something but it's been all day so I think that would be gone by now. He's only done it a few times throughout the day...could it be him just discovering sounds he can make? He is also getting his two bottom teeth. Mind you it's the cutest little cough I've ever heard, but should I be worried that it's an actual cough? TIA