Actually, a human baby at 2 months is called an "embryo," not a fetus.  And they have a heart at that stage, with both a left and right chamber.  I heart science!
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So you're defining a human by the development of their brain?  Interesting.  So those born with abnormal or undeveloped brains are "less human" to you?  I don't think you've thought this one through very much....
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Here's some more science: we're human at conception. We have a complete chromosomal makeup, and are totipotent at the moment of conception, and will always grow and develop as- not into- human beings.
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Hope this helps.