How long is your one month old able to hold his head up for?

My son started picking his head up when he was about a week old and now at 5 weeks almost 6 he does it every time he lays on my chest to look at me and I swear he can keep it up for a minute at a time before flopping it back down. He's even been able to keep his head up while tracking noises (for example his daddy walking across the room) I feel like it's too soon for him to be able to do all this lol