1 baby and 1 yolk sac but no baby on scan

Karen
Hi. I had a scan last week at 8 weeks and saw my amazing little baby with a strong heartbeat. They then said they thought they could see another yolk sac but no baby. I'm going back next week for another scan when I'm 10 weeks but they can't tell me anything more until then. Has anyone else had this? I'm really worried and scared. Thank you x