hey there, my son lachlan is 9weeks old, he is a very good sleeper at night most nights. during the day he wont sleep without his dummy, i dont think its a bad thing because its like a security thing. im not sure wether you breat feed but if not thats more then likely why your son likes his dum because its a security thing.
i dont mind that lachlan has a dummy as long as he doesnt start wanting it at night time