M.F.
I'm afraid the more you try to fight it, the more it will be a problem. Kids NEED to self-soothe and, if we won't take a pacifier instead, he's going to do it no matter what. I was a little trepidatious when my daughter started sucking her fingers, since I sucked mine ALL DAY and ALL NIGHT until I was in 3rd grade, but I didn't do anything to try to stop her as I knew it would be pointless and it was what she had found to comfort herself. Next thing I knew, she got teeth and stopped sucking her fingers. I wouldn't worry about it at this young age and deal with it with your doctor's help if it's still a constant thing in a few years. Good luck!