Hi Karina, personally I wouldn't worry about it. Particularly if you don't like dummies. Natalie won't take one either, though I have tried lots of times with lots of different brands and shapes. I've resigned myself to the fact that she just doesn't like them and will use her hands to self-soothe.
You know, sometimes it isn't easy to get rid of a dummy, and they can occasionally cause sleep problems (you have to keep plugging them in.) A baby always knows where their thumb is, so it could work in your favour. You baby might grow out of it before it becomes an orthodontic issue. Heck, your baby might end up needing orthodontics regardless!! It's not always something you can control