Girls, baby is 3 weeks old. He's been grunting for a week now, like he…

Girls, baby is 3 weeks old. He's been grunting for a week now, like he has a stuffy nose, although it's clean and snoozes, as if something is in his bronchi. We haven't seen a pediatrician yet, but I asked her on the phone, she says yes, babies up to 3 months old grunt. Has anyone experienced this? Do we need to take any action?