Baby has a small cough

This might sound dumb but my son has a little kind of dry cough (no phlegm or anything) for about a week now. It’s kind of sounds like a fake cough ya know where it’s just soft, not a hard cough but he’s only 5 months so I doubt he would know how to fake cough. 🤷‍♀️ I’ve been monitoring it, hasn’t seemed to get any worse and he isn’t showing any signs of fever or any other symptoms but his dad wants to get it checked out. Would you call the dr? What do you think it could be?