Skeptical but hopeful and going crazy

One day late for AF which is odd since I'm like clockwork. I tested 4 days before AF, 1 day before AF and the day of AF because I had tightening feeling/mild cramping on and off for about a week before and never experienced this before so it got me excited thinking this was it but all tests were BFN. I drink lots of water so my urine is almost always clear, could this be affecting my tests or does it sound like AF is coming any second? I'm going to the bathroom checking every 15 minutes! >.<