My pediatrician mentioned the flat spot on my baby's head at his 2 month appt. yesterday. My son favors that side of his head while sleeping on when he is on his back in general. We are trying to keep him on his tummy more often, but I heard that the Boppy Noggin Nest can help while he is on his back. Has anyone used this? I am so terrified that he will have to wear a helmet if this does not improve.