I agree with these other smart ladies. You can't worry about past girlfriends, it will drive you crazy. They didn't work out for a reason. I think if you have this insecurity it may be too soon to be engaged. You are still young and I hope that you are pursuing other things in your life like school and a career. You are at an age in which the whole direction of your life can be determined so do not lose yourself completely into a relationship. I'm a mother hen on that----- sorry. But I do think it is worth thinking about why you are jealous of an ex girlfriend. Some of it is natural and some of it is that we have insecurity. The way to overcome insecurity is from within and the things we do to enhance ourselves. So keep on top of those things and your relationship will continue to grow and the ex girlfriend will fade further and further away. good luck
Judy is right, you have the power here. Men like confident women, not insecure ones. He's obviously attracted to you, he's obviously in love with you and he's obviously done with her. There is no need to reliving the past. She was never an issue in your relationship to begin with, don't make her one now. It's normal to feel a bit jealous and insecure over your lover's past but if you let it consume you, you will be damaging your relationship. There are so many other things to focus on then his past. It's your thoughts that need to be controlled. Don't look at her, don't look at pictures of her, don't look her up on FaceBook or Myspace if she has those things. Just pretend like she doesn't exist. She's no competition, keep that in mind.
You are making unecessary problems for yourself and keeping the past in the future. So what if she Is, YOU got the man! We all have a past and history. Keep her where she now belongs, in the past. He is with you, so enjoy your man and don't worry about what you can't control and life is so much more than just looks. A woman with self confidence will radiate both inner and outer beauty, so don't give anyone that satisfaction of seen you insecure and work on your self esteem. Good Luck!