No heartbeat today

I went in for my first ultrasound appointment. According to my calculations I should be 9w5d. After the ultrasound, baby measured 6w1d and no heartbeat. Meet with my doctor and feels the pregnancy isn't viable and gave me some options. He knew I was having a hard time accepting it so he said I could come back in a week for another ultrasound. I asked if my hcg levels could be checked so they drew blood today and I go back Friday. Am I just holding on to any bit of hope? Can anyone share experiences?