K-
I can only imagine that you are asking this because you are unmarried. I didn't regret it until I became a Christian. GOD is gracious to forgive.
That being said, I am sure that there non-Monotheistic individuals that regret this. I know that you will hear from them.
A question to ask yourself is, how do a feel about the idea of marrying someone who has had 30 (or make up a number) partners.
If you contract an STD, I promise that you will regret the act. Condoms are 100% safe when they, and your sexual organs, remain unused.
JayR