Welllll...
Depending on the profiency of your father, when he did the naughty-noogie-naughty on your mother, it would be an average of about 20 Million spermatozoa "injected" (I love that word, don't you?).
So technically, you had a one in twenty million chance of being born. Roughly. But then again, it might not have been equal, for all lil swimmers. You might have been the first to jump the gun, as it were, or in the first "shot"...dear oh dear I'm blushing....thus getting a clear advantage in the great vaginal excursion of 19-- whenever, nine months before you were born.
So in the end, given those sorts of considerations, the chances of you having been born by "winning" the race, so to speak, would be, and this is a guess, mind you, between one in a thousand > one hundred thousand.
Still pretty good, if you ask me.
I know this coz I'm an anatomy major. I'm not a sex freak, or anything.
Honestly.