I drink fizz juice and have had a fair few lucozades and so far im fine. Try relax, they say everything is harmful thesedays but it we followed every guideline we'd have no lives lol
With all the hype about caffeine lately I can only give you my personal opinion/experience. I am a BIG soda drinker....I drank tons of caffeine with my first two, more than i should have with my second two and the same with this one. So far, no problems.
Think carefully at the title. "Energy Drink" the only things that can give you that beyond regular normal boosts are caffine, nicotine, speed etc. I doubt that you've harmed your baby since it was a couple of times. As long as you dont abuse it you should be fine. You probably had the baby shaking a little and getting a little withdrawl symtoms but you dont want your baby needing that when born because then you're really going to have a problem. It's like drugs for them. Talk to your doctor and see if there is anyway to know while still pregnant if you've harmed the baby. They will have way more insight to this. I hope all is well and that you take care of you and yours!