How many zygotes do you want to kill to test the theory so we could know? I doubt any. I think it's crazy to assume supreme knowledge of the state of our zygotes in any given month is even possible. No cycle is that accurate.
No, but the acceptance of the lining to zygote implantation can be tested.
Look, if you look at my profile, you will see that I am a Jew by birth. Probably described as Orthodox for a good part of my life, and that training, is, in part where I am coming from.
A lot of the traditions you see Orthodox Jews do is avoidance of sin --- violation of the Law.
For example, the Bible permits the eating of only certain insects. Well, the identity of the permitted insects is less than clear in this day and age. We have a good idea, but not ABSOLUTE knowledge.
Ergo, to be on the absolute safe side, ALL insects are avoided for those keeping kashrut, even though we'd be 99.44% sure we'd be OK eating certain ones.
That "safe harbor" --- avoid in the abundance of caution approach is my approach to problems like this.
I DON'T KNOW the correct answer. However, I know the SAFE answer.
And when dealing with accidently killing someone, I would opt for the safe harbor.
Opinions differ as to what is "safe." Yours obviously does.