6 wk scan - no embryo?!

Had my 6 wk 5 day ultrasound (trans abdominal) this week and ultrasound tech was not able to find embryo. She found something that “may be the sac” but unsure. I’m now very worried. Has anyone experienced the same and turned out okay?

For background, I have PCOS and tested positive the first month after getting a “regular period” post IUD removal. Period completely stopped when I had my IUD. This means I don’t know when I actually ovulated.

They booked me for another ultrasound after 2 wks.