im ff so dont know if that makes a difference but my ped said, in general to feed on demand, not necessarily every 3 hours so meaning not necessary to wake if he sleeps past the 3 hours, however not to let go past the 5- 5 1/2 hour point.

ds is only 2 weeks old tomorrow so still testing things out and the first couple of days while in the hospital, i would wake every 3-4 hours to eat, then once home and it was so nice to have him sleeping, i would let him sleep and not wake (he wouldnt go more then about 5 hours though) but then i realized that when he would wake, he would be so hungry, that he would be gulping so fast, that would create problems as well not to mention the crankiness and crying from being hungry so starting yesterday, i started waking througout the day at 3 hours to eat and at night, not wake at night. then today, he started waking up on his own at 2 hours and 45 minutes lol consistently. hopefully during the night he doesnt do that but i have a feeling, he has started a little pattern.