M.S.
G.,
Pregnant or not, you really should be drinking water. Artificial sweetners aren't good for anyone, period.
That being said. Have you tried squeezing fresh lemon, lime or both in to your water? Have you tried ice cold and or room temp? I for one LOVE ice water if I have fresh squeezed lemon or lime in it, otherwise I love room temp water. You could even squeeze orange, grapefruit, whatever flavor you like.
Now an alternative, or I should say, something to have in conjunction with water that is good for you, Vitalyte http://www.vitalyte.com/. You can find it at REI or most running stores. If you absolutely can't stomach water than add a little Vitalyte to your water, just to flavor it, plus you'd receive a few other benefits but really plain ol' water would be best.
Congrats on your pregnancy,
M.