My ds (18 weeks) has recently started to yawn upon waking up. He does this first thing in the morning and sleeps from about 8pm to 7am (waking once for a feed). He also does this upon waking from naps (have managed to get him to do 3 naps which come to a total of around 3 1/2 to 4 hours)
I cn't understand why he's still yawning but if I try and get him t go back to slepp he screams blue murder.
Many baby books make a big thing about a baby yawning when they are tired. IME this only applies if a baby starts to yawn after a period of being awake. Yawning when waking up is just body language that says 'I'm coming round, hang on a bit whilst I get myself ready for the day'.