Measuring 6 days behind on ultrasound.

Laurel • 👼🌈👶👼👼 due 11/6/21 with a 🌈👶

Just came from our first dating ultrasound. Based on when I ovulated (I know pretty precisely) I should be 6w6d. The tech this morning said it’s looking like 6 weeks. I am devastated. Had a mmc back in April at 19 weeks. Has anyone had this happen and get a positive outcome?