7 week old sucks his thumb

My 7 week old is sucking his thumb and I'm not sure whether I should intervene somehow... by giving him a dummy maybe?

I am breastfeeding on demand so I am reluctant to give him a dummy as this might mean he sucks away on that when he is in fact hungry (if that makes sense)

My concern is that in the future I can take away a dummy, but I can't remove his thumb... do you reckon he will just outgrow it and its just something new he has discovered for now?