hey thats what happens when u cut a banana p-stem....dont worry it will push out on its own just give it more water and you will see it push out :D

Just try to be patient. Not sure where you are, but around here things were delayed about 2 weeks due to a relatively chilly Spring (my peonies are just coming into some bloom and normally they are at peak around Mother's Day. Well, bananas are really tropical and it's going to take some prolonged warmth to encourage them. (My bananas are in about the same state as yours--all but the Chinese and Japanese which are pushing active growth.) Good luck!