You’re not alone. There are people who have trouble understanding that someone they love dated, or was married, before. The fact that this person isn’t a virgin, or had more experience than they did, can become a big problem. I would encourage you to understand that everyone has a past, but that she’s with you now, and that she doesn’t cheat on you, and she wants to be monogamous with you. But, if you can’t do this, and you can’t be okay with the fact that she did have sex with other boyfriends before you, you won’t be able to move on with her. If that’s the case, then you should probably find someone to date who has the exact sexual and social background you want her to have, in order for you to feel okay with things. If this incompatibility is a deal breaker for you, you should accept it and move on.