Drinking with TTC

I'm looking for everyone's opinion on drinking while TTC. Because Valentine's Day was Wednesday and hubby works late, we won't be celebrating until Saturday. We're going to dinner at a really nice restaurant we like (I also happen to have a buy one get one free entree coupon since my birthday is next week). This place has a killer Sweet Tart Martini. I'm not a big drinker to begin with but I love these things. I'm expected to ovulate on Friday. Obviously I wouldn't want to do anything to hurt a baby if we were to conceive this month. What's your opinion? To drink or not to drink?