7 Weeks Empty Sac

Good morning. I had my ultrasound last week, July 12. Based sa result ng US, 7 weeks na ang gestational sac but empty, walang embryo. May chance na maging anembryonic pregnancy or blighted ovum. To confirm, will take another ultrasound this coming July 22. Anyone po na may ganitong case na empty sac pero after the next ultrasound, nagkaroon pa rin po ng embryo?