Is it ok to add Crystal Light to my water while pregnant?

I'm trying to drink all the water I'm supposed to, but it's so hard. I have the little Crystal Light single packets, but they're sweetened with Aspartame. Is it okay to have them anyway? I'm trying to be good and do everything right, and I know I need to be better hydrated, but the nausea gets worse when I try to force the water down.