Well when you get married your fiance will then be your husband and you will then, as his wife have the security of being in the marital home. If it all 'went wrong' then you would have the same rights as any other wife. As far as giving up your career, then as previously said, you can take maternity leave and then return to your career. What would slightly worry me is your feelings so close to the marriage, it seems as if you have not really talked to your fiance about the legal issues that do crop up when you get married and that it would seem sensible to discuss.