With DS1, I had a negative blood test the day I was expecting AF to show up. I was cramping so bad, I figured AF would show up any minute but after two weeks of super strong cramps without any sign of my period, I tested with an hpt. The darkest bfp I've ever seen and he's now eight and a half.
With DD2, my beta at 13dpo was 36 and my dr was predicting miscarriage. She just turned 4.
With DS2, my beta at 14dpo was only 54 and he's now a healthy happy creeping crawling 10 month old.
That number has to start somewhere, right? And not everyone has super high levels to start with. Remember, it's not the starting number that matters so much as the rate it rises at.