How long have you two been together? Has anything happened in your relationship such as an infidelity or other sort of "trust" issue? How old are you two? Have you both had serious relationships before eachother?
Sorry for the questions but sometimes a little more information can give you a better grasp at a situation.
I do want to suggest that taking a break is not a good idea. You would be doing it in an effort to "test" her to see if she wants it bad enough? How is that a good idea? You want to spend the rest of your life together right? Well, that means finding a way to communicate to get whatever is bothering her to the surface. When your married you can't just "take a break" when something is going on. Have you thought about couples counselling to work on your communication with eachother? A lot of churches (and I'm not trying to assume a religion or talk about it, I'm just trying to make a point) require counselling for a couple before they get married just to ensure they are ready for the committment and work it takes.
I am more than willing to give you any more information about how I see your situation if you are willing to share more details.