My 3 month old has been waking up suddenly the past few nights with hysteric screams as if he's having a scary dream. It also seems to occur around the same time -- approximately 40 min after he falls asleep. When I go into his room, he seems to still be asleep and once I pick him up, sway with him and gently shush him he is competely asleep again. Has anyone eXperienced something similar? My poor lil guy!!