Well, you don't know for sure that she'll do that. BUT, if she desides to go out with her friends sometimes to clubs, you will just have to learn to trust her. Even in a relationship, sometimes you just need a night out with the girls/guys. But, if she begins to want to go out to clubs/bars on a regular basis, ask if you can tag a long, or just sit and talk with her and tell her you feel a little uncomforablte with her doing that all the time.
Good luck with that, But I hope you don't even need the advice of this page. Maybe she won't be that fascinated with the bar scene anyway.
Never regret something from your past, everything happens for a reason.