Some parents tend to worry about their babies sucking their thumbs. But there are some good things to be said about thumbsucking.
Babies can make themselves content when they suck their thumb. There is no need to hunt all over for a lost pacifier. And with all the worry about BPA and unsafe plastics, a thumb is probably much safer and healthier for your baby.
So, don't push the pacifier on your baby, especially if the thumbsucking isn't a constant solution for baby.