As I understand, the blastocyst is a state of a human being in the early stage of its development, having in turn developed from the morula, and the zygote (the first cell).

If you want to argue semantics of the words or the phrase, we can do that. If you want me to use a dictionary to justify my use of the words "human" and/or "being", I'll do that. If you want textbook (medical) definitions, you can have it right away at https://goo.gl/ZFDcbg. And if you'd like more scientific literature backing, consult https://goo.gl/zXpbAu. If you are willing to cede that the nomenclature fits, but would like to now rank human beings by worth in relation to stage of development, I would like to provide arguments for why you shouldn't do that. Finally, if you have reconsidered everything, I would invite you to the Way, the Truth and the Life, as scary as that might sound. Peace be with you and yours.