Women are very emotional. Our whole lives and bodies are built around growing and having a life inside them. Most of us dream about having kids when we are little. That is just how we are. And I know men are just as excited about it (most of them anyways), but its so hard to try to express how you feel when you know you have another human being growing inside of you. It is a very very sad thing to lose a child. Whether it be by miscarriage, still birth, or worse, after the child has already been born. The best thing you can do, is be there for her. Let her know how you feel, and do your best to try and help her through it. It might take a while, and it might be tough, but she will be forever grateful in the end. And maybe after time has gone by, discuss trying for another baby after you are married. I know how stressful a wedding can be, and stress increases the chances of a miscarriage, so that is a possibility. But just try to be there for her as much as you can.