L.S.
Hi L.,
Your story sounds like my story! My son is now 7 months and is just beginning to go for longer 2.5-3 hour stretches. Many times 2 hours is still his limit, though. Up until he was about 3-4 months old 1 hour was his max!
I used to worry and ask the pedi and other moms how long their kids stayed awake, and then wonder if something was wrong with my son. I finally came to realize (and learn from the great Healthy Sleep Habits, Happy Child book) that my son just needed more sleep to be happy and I was also very tuned into his needs. Lots of families ignore the sleepy/cranky signs and keep their kids awake too long.
You are a good mama, tuned into your son's needs, and putting him down to nap instead of dragging him around everywhere that you want to go or overstimulating him when he just wants to sleep. Like another poster said, as long as he is content, growing well and eating well, and developing fine, everything is a-ok! We just need to enjoy the extra nap time our sons give us instead of worrying about it. I know, easier said than done! :)
Warmly,
L.