Some motivations for not having sex before marriage are wrong. They can be just as wrong as having sex before marriage. One such wrong motivation is fear: fear of being found out, fear of pregnancy, fear of a disease, fear of the opinions of others.
One proper motivation for doing God’s will is love of our neighbor. The neighbor we are to love as ourselves can be our neighbor’s daughter. Also, your neighbor can be one who will be your wife. And your neighbor is your parents or your future wife’s parents, both of whom would be hurt terribly when your sin is discovered.
But the main motivation is the love of God. Love God for the salvation He has so freely given. Love God for all things, including the sexual desires He has given. Submit your sexuality, along with everything else you are and have, to Him. Let your love for Him drive you to strive to please Him in all of your conduct, including your conduct on a date.