If you feel ok with yourself, you were not in a monogamous relationship at the time and weren't purposefully trying to attack other monogamous relationships, then I see nothing wrong with it. Not every girl does it, yes, but that doesn't mean it's wrong. It's just personal preference.
However, from the fact that you made a thread about, it sounds like you do feel a bit guilty, especially given that you're now in a relationship and he knows about your past. Personally, I see nothing wrong with your sexual history but you're probably worried about what your partner think, not what a stranger on the internet thinks! Communication is key in a relationship: you should talk to them about your concerns/worries and ask if it does make them uncomfortable that you've had sex with a lot of people in the past. If they don't feel that way then you now know that and shouldn't have to worry about it! If they do, it's not the end of the world. You can work through it together. It's only if it's something which they refuse to get over or discuss, however, and it's affecting your relationship that it may not work out. But if they refuse to trust you or so easily feel inferior compared to you, it may not have been the best relationship anyways.
On the off-chance that you were supposed to be in a monogamous relationship when you got 'a bit naughty' and your current partner knows about this event, then still talk to them about it. Acknowledge it, see how they feel about that fact and ask if there's anything you can do to alleviate any concerns. Relationships need communication.
You are certainly not the worst person around. You've had sex, not killed someone. It's ok.