Yolk sac but no fetal pole at 7 week ultrasound

Elyse

Hi there! My cycle is usually 31-33 days so I usually ovulate on day 16-18. I went for a scan that was, according to my last period start date, 7 weeks. The yolk sac was visible but not the fetal pole. Could it be off bc my cycles are longer and I ovulate later? My dr has me come back next week at week 8 to do a repeat scan. She mentioned anembryonic pregnancy which now has me scared to death. Does anyone have any experience with this? Thank you in advance!