HI, I have an angel/textbook baby and he does the same thing more or less. During activity time, he yawns the whole time and doesn't give ANY signs of being tired except when he is OT. When it is nap time though, if it is not the right time and he UT or OT it is practically impossible to settle him. I just keep an eye on the clock and considering he is almost 3 months, around an 1 - 1 1/2 hours of A time and I start to put him to sleep. His eyes do get bigger and a little red around the edges when he is tired but not always. Wish I could be of more help. Actually, I have a question for you LOL, how did you extend his A time?