Before my DE cycle started my RE said they would probably get at least one embryo to day five. He said there would be a good chance there would be extra embryos to freeze. But he also said not to worry if there were not any extras to freeze. He said having extras in no way would change the outcome of the one embryo they would transfer. Sometimes they have lots of extra's to freeze and sometimes they don't have any.
Try to take comfort in that. It sounds like you have a really good looking embryo. I'm wishing you luck!