Existance and Laws of probability

Have you ever wondered that your existance in this planet is just by a mere chance or governed by laws of probability? Though Science would say, one's existance was decided nine months(or lesser) before when your genetic material was decided... but your characteristics and what you are now, would it all have changed if you have been born a second earlier or later?? Do you beleive, You(however u define it even in a deepest philosophical sense) could have been born in a different time with different genes in a different part of the world? If you seperate soul from body, then you could say my arguement holds good.. though scientifically I am not sure if I am making sense or even otherwise :)... But thats my thought for the day, however wierd it sounds.. or however profound it may come across... or is there a big flaw in my arguement??