I very rarely used to drink coke before getting preg, but have found that its another tastebub that has changed for me. I dont drink it really during the week, but on the weekends, i might have 1 or 2 cans, and i feel abit quilty about it, but, as Lil MG said, they dont ban caffine all together, so i think in moderation, you should be fine. My biggest concern with the coke mainly is the sugar.
Before being preg, never had sugar in my hot drinks, but, now, always have sugar.