Help with ultrasound results?

AJ • Expecting #2, 12/6/21 🌈 Baby Girl born 2/19/20 💕 2 MC: 10.5.18. & 3.25.19

I went in this morning for a follow up ultrasound. I should be 7 weeks, 5 days today. They performed the ultrasound vaginally again, as my first ultrasound they were only able to see the sac. Today they were able to find baby and the fetal pole, measured heart beat and indicated it was only at 76. However they also stated that the baby was measuring at only 6 weeks, 1 day. Which seemed far off from what I should be even if I ovulated later.

I called the nurse to ask if I should get the follow up ultrasound scheduled that the tech told me I’d need next week. She instead started listing off the precautions for miscarriage and told me when to seek help, and that I should basically prepare myself for it. A doctor hasn’t seen my ultrasound scan yet and is supposed to be calling me back but I am left uneasy and a crying mess in the middle of my work day.