Should this really bother me that much?

Guest

Me and my gf have been together for almost 4 years now. She is the only person I have ever had sex with. The problem is that she has been with about 15-20 guys. She was upfront about this from the start and this was all before we even met. It always bothered me but I fell in love with this girl! Recently we have been talking about getting engaged and for some reason I am having a hard time dealing with this. I think I can trust her its been 4 years and we have never had any problems but all I think about all day is how many guys she has been with and I begin to doubt whether I really want to marry someone who has been with so many guys before. It also makes me feel like having sex means nothing and we don't really have anything special going on and everywhere we go it seems like there is an ex bf or "friend" that we run into, it drives me crazy!

I know it's a little late in this relationship to decide I dont like something I knew all along. I dont know if my feelings have just changed and thats why it bothers me more or what I should do?

This girl is amazing but knowing she has been with all of these guys and thinking about it all the time is changing the way I feel about being with her and especially getting engaged.