hi sherri,
sorry to have been so long in replying.
I'm no expert but.... I would take a day (or two) to step back and look at your routine and check. Are you following EASY? Are you doing E straight after a sleep? What is the total number of naps/hours of daytime sleep? Go back to Tracy's book, if you have it, to re-read her words of wisdom.
It may well be that you are doing everything right and ds is just extra sleepy or growing or making up for a bad night.
Remember babies are all different in their needs, maybe he needs more sleep than others! I compare dd to other babies and wonder why she eats so little, but I have to remind myself she is a small baby and is eating what she wants!
HTH
keep in touch
juliet