Okay my daughter was a good sleeper from the get go. She got up when she was supose to and slept when she was supose to. She started sleeping all night I believe at 2 and a half month. Recently in the last month or two she has been tossing and turning alot at night. I make sure she isn't cold or to hot and check her diaper and change her but she still tosses and turns. She gets to the point to where she hits her head on the crib one to three times. It worries me. It seems constant and she awakes crying and whining a couple times. Is this normal? What can I do? How long will it last?