It depends on what this "scar" looks like. Based on your description, it is only sort of a scar. It is where your "female" genitalia grew into male genitalia while your were in your mother's womb - somewhere in the 2-3 month area. No need to worry about it. And, hey, ask your parents - maybe you'll get a chance to teach them something.
Ask your doctor, if he or she is the doctor you have had all your life. If it's normal, he'll just look at it and tell you. If there was something interesting that required minor surgery years ago, it should be in your records. You have the right to know.
Unless you have a really bad relationship with you parents, why not ask them? they probably know what it is, most of all your mom. It is a good idea to have good communication with parents. In the future, you might need to know other medical information from them as you start a family and get older. Good luck.