As long as you stay under 200 mg of caffeine you should be ok
They have caffeine free soda..that's what I drink when I really need a coke. And they just say to cut it down not necessarily quit completely. It passes the placenta so the baby gets all the caffeine you drink. My doctor also told me there's some studies that show caffeine increases risk of miscarriage. I'd ask your doctor though. I think they say its okay to have the equivalent of two cups of coffee.
As long as ur drinking water to I think u should be alright