Start doing some relaxation. Bismuth products (I think it's called pepto bismal in the States), is excellent for smell if that's your concern. If you relax, the gas can usually pass a lot better. If you're nervous, be a bit concious of how much air you're swallowing without realising. All I can say is avoid the "gassy" foods and find some way of accepting the fact that it may occur and think in advance of ways to deal with that on the day if it does happen. I know how much weddings can be a nerve-racking experience...think about the times throughout the day that you can grab a "breather" away from it all where you could relax in peace if you start feeling pain. I wish I could offer you some better advice but to date this is all we have...relaxing and accepting.