DS is now 11 weeks old. He was originally sleeping 6/7pm to 2am (7/8 Hours) He'd then wake at 2am feed and nearly drop straight back off to sleep for another few hours. DP goes to work at 4 so that usully woke him up so he'd feed and go back to sleep till around 6/7am. He'd have about 12 hours sleep at night.
Now he sleeps 8pm to 4am (8 hours) but really doesnt want to go back to sleep at 4am despite being grumpy tired.
Any ideas how I can get him back to sleep?