Help! Miscarriage question

Laur

For the past three days I have had brown spotting. Thought I was 5w5d but today the ultrasound read 6w1d. They saw a yolk sac & gestational sac, however they didn’t see a heartbeat. Doc thinks it’s a miscarriage. I’m going back in two days. (Thursday, since today is Tuesday)

Is it to soon to see a heartbeat? Do you think I’ll have a m/c since I’ve been spotting?