Can dehydration affect how light your period is? Since I stopped using birth control troll (almost two years ago) my periods were always light, 2-3 days, and I could get away with using light flow tampons. I asked health care professionals about it, and they said there is no reason for concern because it was consistent. Lately I have been increasing my water intake and have noticed a heavier flow (bleeding through my tampon, which I have never experienced before). Is that a normal result in drinking more water regularly?