My ds2 is 5 months and normally sleeps pretty well, but last night he was really unsettled until I gave him a muslin square to hold, when he went straight to sleep. He's quite a sicky, dribbly baby so he does have muslin around a lot. Is he too young to have chosen a comforter? A muslin is an easy one for him to have (machine washable and cheap and all that) but do I need to worry about him having it to sleep with, or am I being paranoid? Thanks!