start now although you probably won't get more than a minute at a time at this point - work up to greater lengths of time (unless you're like my DD at which point, you'll only ever get 1 minute at a time )
We started with Will right away. You're obviously not going to put her on her belly for five minutes, but our pedi recommended starting with 20 - 30 seconds a few times a day. By doing that, he had incredible head control very early on.
We started at about two weeks. He used to try more to hold his head up, now he just likes to lay there lol. My Pedi says to just do it several times a day, even if it's only for a few seconds.
start now and start by doing it on your chest. the baby remains so much more calmer than laying him on the floor. we have been doing chest tummy time since birth and i just now started boppy tummy time (in which he can only stand a few mins of but it's getting better) lol.
Re: when to start tummy time?