When Danielle was 3 months old she slept 10-11 per night solid and during the day she would sleep an hour maybe 3-5 times per day. Her sleeping pattern is about the same now and she's almost 5 months old. If they don't seem cranky due to not enough sleep I wouldn't worry about it. I got a flyer from my Mother's Group saying at this age they change their sleeping patterns but if you aren't phased what they are doing don't worry.

I hope this helps.