how old is ur baby?

my experience: sometimes it is really hard to convince ur baby to stop using the pacifier. the same story goes for sucking the thumb.
usually the baby is really nervous when we try to stop this habit.
but i know that kids who started going to nursery/kindergarten usually give up this habit quite easily and without any big stress...why? because they see that other kids don't do that :o)
it actually stops by itself then :o)

i don't know how old is ur baby, but if u i am not sure if it would be the reason for him/her for not gaining weight.
maybe u need to consult a doc about this?

good luck!

If you're looking for a problem, you're probably gonna find one.