Did anyone take ChickenPox shoot during medical exam ?

My doctor said if I did not have ChickenPox disease (Shui Dou) when I was a child, I need to take the shoot. She said I need to ask my parents. Question is, even if I never had one before but I telld her I did, how can she or anybody else tell I lied. then I don;t need to take the shoot. Any advice ?

Thanks a lot.