embryologists from around the world had to say on the topic:
https://prolifepages.wordpress.com/when-does-life-begin-senate-judiciary-subcommittee-hearings-april-1981/
and for a more detailed look at the science involved:
When do human beings (normally) begin?
“scientific” myths and scientific facts
by Dianne N. Irving, M.A., Ph.D.
http://lifeissues.net/writers/irv/irv_01lifebegin1.html
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In all honesty, are you open to the possibility that a being with a human mother and a human father is in fact a human being?
Do you honestly want to search for the truth and let the chips fall where they may? ... including the possibility that you might need to alter your beliefs to bring them into conformity with the truth?
Or are you trying to defend your beliefs with a willingness to ignore or distort the facts in order to do so?