Urs - Yikes, yeah, it sounds like you need more water! 8 glasses a day is the minimum. In more exact terms, that's 2 liters of water per day. If you work out and sweat a whole bunch while you do it, that might need to be increased to 3 liters. Some days I drink as many as 4 liters of water (not counting coffee or other non-water drinks!) because it's a hot day and I'm sweating, or I'm doing lots of yard work or something like that.
Remember that your body stores toxins that it can't get rid of in your body fat. So when you don't drink enough water, that stuff just builds and builds. You might get headaches or feel crummy the first few days of drinking enough fluids because the toxins re-enter your blood stream.
Just think of every glass as a rinse for your body, and every trip to the bathroom is you getting rid of more of the junk stored in your system.
One thing you can do to help you is to keep 2 separate 1-liter bottles of water filled and nearby whenever possible. When I do that, I'm less likely to make the excuse that I can't leave what I'm doing to take a minute for a refill. As silly as that sounds, I'm constantly getting absorbed in my work to the point that I forget to eat or drink for hours, so if I have the water at hand, I can just drink it as I go. Haha
Miracle - My HSG was pretty crampy even with 800mg of motrin before hand. It didn't last very long though, so don't fret too much! The tests are usually over pretty quickly. I hope yours goes well!
Cupcake - This group is really great for keeping us all in line, isn't it? I can totally relate to these gals making me want to do better! Especially when I hear all the great success we have going!
AFM -- DH and I also did cheat day yesterday. I forgot to take meat out of the freezer to thaw the day before, so last night I didn't have anything ready to cook. I hate using the microwave thaw option because the meats always turn out rubbery. Blech! So we had some Panda Express (with steamed veggies instead of noodles!) and I had plain water instead of a soda or other sugary drink.

So I think I didn't do too badly there.
Been keeping up with the challenge for this week. Yesterday I was a little short on water, so I didn't get as many trips to the bathroom in as I did on Monday, but that's all right. I'll just drink more water today!