My son is 3 months old and all of a sudden he has been sleeping soooo much more during the day. He has always been a great nighttime sleeper (10 hours + at night) and a crappy napper...but all of a sudden it seems like all he wants to do is sleep all the time. He wakes to eat every 2.5 to 3 hours (breastfed) except for his ten hour stretch of no food overnight while sleeping. Should I be concerned about his sleeping? Or could it be a growth spurt or teething?