No worries, the yolk is attached to the tadpole. They will look very untadpoleish for a couple days while they feed on the yolk while being attached to the side, rocks and any other stuff in the tank. When they get the "normal" tadpole shape and are no longer stuck to the sides but instead swimming around, that is the tie to feed them. This can be anywhere from 2 days to 2 weeks depending on water temperature.