I feel really bad.....?

Recently I had to do this testing for school, and when I had to say the opposite word (ex. the opposite of day is night), when the lady asked me what the opposite of ancient was, I said young! Omg I don't know why I said that, it was an accident, I was just really nervous and I kind of just blurted it out. I feel so mean! What do you think? And am I overreacting?