Personally, I just decided to cut out all soda altogether once I became pregnant (and I am a major caffeine/diet soda freak), mostly because of the chemicals involved in general. I just figured I could tough it out for a while. But man, as soon as I am able, someone had better bring me a huge deli sandwich and a big, glistening, caffeinated diet soda!
Caffeine free is good but I would still limit soda because of sugar content and sometime the carbonation can make u more bloated. Good luck to u