I am now 4 days late, I have had menstrual cramping for the past 5 or 6 days when normally I only cramp 2 days before my period. I took a HPT when I was 2 days late and it was neg.
Cramps are indeed normal.
Usually it's the embryo implantting itself on the uterine wall that causes these cramps. Even a little spotting is normal. So you drink gallons of water to make yourself have to. Well that is diluted urine and the results can't be trusted. I did it with my daughter when I was pregnant.