Avoid most diet drinks as they contain artificial sweeteners which are bad for you and the baby.

Also Caffine in the first trimester can increase the chance of miscarriage. I am a big coffee and tea drinker and just before I found out I was pg any caffine would make me feel violently ill. This lasted until about week 23-24 when suddenly my newest craving became coffee. I do try to limit it as I have noticed much more movement from bigfoot if I have too much coffee, usually at night when I am trying to sleep.