Is a baby one thing outside the womb, and another inside?

When you are 20 years old, are you a different species from when you were 19? When 19, 18? When 18, 17? When 9 months, are you something different than you were at 9 weeks? When 9 weeks, are something different than you were at 1 week?

No, you weren't. Human life is defined by conception.