DS 19mo is currently taking anywhere from 20 minutes to an hour and a half to drop off to sleep at bedtime. He doesn't cry, just chats away in his cot and plays with his toys. Has always had a strict routine, is up around 7, naps around 1pm-2.30 and in bed for around 6.45/7. Me going in makes no difference and he's self settled at bedtime for months so don't want to change that but is there anything I should be doing? Is this normal?!