you can have soda and candy in pregnancy.
if u drink caffine drinks its best to keep it minimal, no more than 3 servings of caffine is probly safe iv read.
all i would suggest is try not to have more than the recomended daily intake of sugary things. just because it could cause diabeaties and make u gain weight u cant get rid of after the birth.
i went all out on chocolets last time i was prego and was 10kg hevier than my pre pregnancy weight even 2 years after!
You do need to gain weight for pregancy but its best to gain from the healthy foods!
best wishes!