is this a symptom?

I've been taking metformin and prenatal vitamins for 3 weeks now, and I've noticed a HUGE change in my urine color. I normally have a darker color of pee but lately I've noticed that my pee is VERY clear, like water, with a slight, hardly noticeable (only when I wipe) yellow tint. Any one else have this who took metformin or prenatal vitamins? Could it be a pregnancy symptom? I know it's a good think to have clear urine but I'm a little worried mine is TOO clear!