This is all totally normal. My daughter does the same thing, and has been since she was about 4 months old and could roll over. She is a fabulous sleeper at night and for naps, and doesn't appear to be tired during the day or when she wakes up. If he is happy during the day and not grouchy all day long, rubbing his eyes all the time, or yawning all the time, he is just fine. My daughter started to be a lighter sleeper the past few months (she's 11 months now), and she seems to be moving around a lot more now, and wakes up even if you just open the door. We turned the monitor down so we can hear her crying or talking, but can't hear every move she makes. We sleep a lot better now, and so does she now that we aren't checking on her all the time! Tell your husband to relax and not worry- and if that doesn't work, talk to the advice nurse at your son's clinic or to your pediatrician if you have an appt. soon.