8 wk US showing 6 wks

Amy

So due to a recent MC, when I started spotting and cramping this weekend I was concerned for another so called for an early appointment. According to my last MP I am 8 weeks today. I had a vaginal US that dated the baby at 6w1d with a heart rate of 143. They told me either the baby stopped growing a few weeks ago or I am not as far along as I thought. But I am so sure on my dates 😭 Waiting for blood work now. So confused guys... any similar stories?