My 10 week old Dd normally sleeps for 3-4 hours during the day - generally spread over 3 naps. Last night she didn't wake for her 3am feed so slept through from dream feed at 11pm till 6am - great we thought. However it has completely thrown her day time routine and she's barely slept for 90 mins today. Is this normal? Are we in for a tough night tonight?!