how do i add a sims it says something werid

I added a crib and i made the house bigger while i was waiting for the stork to come and i moved the crib to make room and 7 hrs went by and it shows i can add a sims but everytime i try it says i got to wait for the new sim to arrive and i tried to add a abior and it says the same thing please help i cant add anything or do anything!!!

You can't add more Sims til the baby is born.