Hi According To My Last Menstrual Period I Was 9

Hi according to my last menstrual period I was 9 w 1 day pregnancy on the day of my ultrasound . The baby measured 6w 1 day with no heart beat. The doctor gave me a 5% chance and asked me to come for another ultrasound in a week. What can I expect . Is this even possible to be 3 weeks off. I have pretty regular cycles around 28- 32 days . Is it possible to ovulate late . Please tell me if I should ask for blood work . I am devastated and looking for answers