you can tell you've had kids by looking at your cervix opening - a different bit to what i think you're talking about.

it would be the same as your skin, if you've cut deeply you can get scars where it has healed, or if it is a smaller you won't see it after it's healed. but it's an area that can heal quite well and with minimal scarring. lots of women get tears in their perineum and vaginal walls from giving birth and they generally heal well after a period of time.
so it would depend on how you normally scar, how big and deep you've cut - and even if there were scars there the dr could not determine what caused it.