okay I've said this before and always get criticized, so, I'm ready and waiting for the American christian right to press that little red arrow and say my comment is bad advice but...
America has the highest divorce rate in the western world and its because of people like you. Allow me to explain. If you're not going to have sex til you get married, that pushes you into a situation where you're in a rush to get married. every girl you find you assess her and scrutinies her as being The One, or as your virgin popping wife. Then when you think youve found her, you race into a married in your early twenties, loss your virginity, live together for 2 years find out you have nothing in common and get divorced. In America the younger the age of the married couple the higher the divorce rate. Just to put this in to perspective, If a couple marry at the age of 24 there is only a 20% that marriage will last 2 years. And I've said this before on this web page and had people comment, that just because it happens to other people doesn't mean it will happen to you. The arrogance of that argument is amazing, ignoring a massive divorce rate simply because you feel you're different to the rest of the American population.
So, your philosophy "to find the one special girl, married and live happily ever after" has some pretty massive flaws. I think a more responsible, logical attitude is to stop assessing girl friends as potential wife or "as The One" ; and instead have sex with who you want to, live together and get married at an older age, when your more mature, and able to choose your life partner better, and when the statistical chances of it lasting are much better.
But to answer your question. I don't think you will regret having sex out of marriage, but just having sex because