I have an 11 week old son who cries / screams hysterically every time I put him down, whether it's in his moses basket for a nap during the day, or at night trying to get him to sleep. There is no routine whatsoever as the only way he sleeps is next to me or in my arms. Should I be concerned about this, could there be an underlying problem or illness or is it just a case of him being a very clingy baby ? Please help !