Gestational sac and yolk sac, but no fetal pole

Per my last period I should be 6 weeks and 6 days today. I got an ultrasound last week and the tech saw a gestational sac and yolk sac but no fetal pole.

I went today and the tech said that my yolk sac looks bigger but still didn’t see a fetal pole.

My doctor said my progesterone levels are good and my HCG was high enough that there should have been a fetal pole/heartbeat. My doctor said it’s possible this might not be a viable pregnancy and I may be having a “missed abortion.”

I’m getting blood taken Friday and another ultrasound on Monday. Has this happened to anyone and they had a good outcome? I’m a damn wreck.