I personally wouldnt drink aspartame while pregnant, my doctor said not to. But there are worse things you could be doing for sure. I dont actually know if it would harm the baby but it is cancer causing so i think why drink it?
I read that its ok to drink, unless you have PKU, then you should avoid it. It's ok in moderation, just like everything else.
My dr told me to drink that over soda so i think youll be fine