Please help me... measuring way behind

I went in for my ultrasound today at 7w3d. Using an transvaginal ultrasound, baby was only measuring 5w5d. Because it was so small, no heartbeat was seen. I’m pretty positive of my dates, as I started taking progesterone 2 days after ovulation. As such I don’t think I could’ve ovulated any later? I go to the doctor tomorrow for results but I’m really discouraged.