Hi M. -
Tell me about it. I have a high need baby/toddler - he is going to be 2 years in May and the most he sleeps at night is 1-2 hours at-a-time. This is indicative of a "high-need" baby. You may have one. They do not sleep through the night until they are around 3 years old. I still nurse him and we co-sleep because NOTHING worked on getting him to sleep longer so we make things as easy on "us" as possible - this is easy for us this way.
This all started for us when he was four months old and started sleeping 3-4 hours at night. (I have big babies too.)We thought we were heading for restful nights. But that lasted three days and that's how these kids are - they do something for just a few days in-a-row and you think they are getting on a schedule only to change everything and this goes on and on. You can count on this with these kids - unpredictable and no schedule.
You are very fortunate if your son is happy - ours had all kinds of issues and I'm still b/feeding him due to food sensitivities/allergies and intestinal issues, reflux, etc... and he demanded to be held constantly for the first year.
If your baby continues this sleep then you can go to www.askdrsears.com - this site saved us because he knows all about these special little babies and you can read on sleep issues and lots else - very good information and advice backed on his 30+ years of research on all types of children/babies.
Many people do not get that these babies just don't sleep - you can also go to yahoo's www.fussybabies.com (I think that's it) and get support there from lots of mom's that know what it is like to have a high-need baby. Some are mildly high need and some are intensely - like my son - high need. If your son is like this, he sounds very mild to me - that is a blessing. At any rate, you just live for the moment and parent them with a lot of love and understanding. And, you soon come to accept that you will eventually get sleep - until then you keep your life low-maint. and low-stress as possible - it teaches you to slow down and keep things simple which is a lesson all of us can learn.
GOOD LUCK!!!
Alli