I just took my son to his pediatrician for monthly regular check up, the pediatrician said no tooth yet is not a problem ah. Some old people even say better to have the first tooth later tim ... but I'm not sure why ah
My BB also does not know to turn over and not having any teeth. The nurse said it's also common especially in such a cold winter time that baby worn too many clothes. Hence they cannot turn so easily. I think we can wait for some more time.