You don't have to spend a lot of money to get away with your fiancé. Spend a night or two in your favorite nearby town; while you're there, treat yourselves to a special dinner and splurge on dessert. During the day, go sightseeing or visit the local farmers market. Rent a bicycle built for two and ride around town together (also a fun way to get some exercise). If you and your man love the outdoors, go camping and take a scenic hike in the woods.
The only rule is whatever kind of getaway you choose, keep wedding talk to a minimum!