Concentrated urine?

Well, I'm on cycle day 45. Got a faint line on a cheapie a few days ago. Anyway, I was talking to my friend who is an ob nurse, and she noticed how much water I was drinking as we sat there. It's just normal for me. I carry two bottles in my purse, and probably drink ten or so bottles a day. She said that there is a possibility my urine isn't concentrated enough for the hcg to register on a home pregnancy test. Of course, I could get a blood draw, but I'll wait another week for that. Then I was told that water intake should only be half of your body weight in ounces. I drink much more than that so I should probably cut back. Just wondering if any other ladies had issues with their urine being too diluted? And if so, did you drink juice instead? Stop liquids at a certain time the night before you tested? Do you drink coffee before you test in the am?