I see where you're coming from, but in this situation I wouldn't get too worried. I mean, if you were talking about getting married on Thanksgiving, Christmas, New Year's or even Halloween, then yeah I'd say I don't think that's a good idea. But Valentine's Day? Nah. It's one of those holidays that people either forget about (i.e. husbands lol) or people just exchange a card and a box of chocolates. Think about it. Older couples most likely just exchange a little gift on this holiday, if anything at all. So I don't think attending a wedding would screw up any plans. Younger couples are more likely to make dinner reservations on this holiday. But how romantic would it be for a new, young couple to attend a wedding on Valentines Day? I don't think you have anything to worry about.