6 weeks no baby / ultrasount

Suma
Ladies,
Im so stressed, i went yesterday to my GYN and she did abdominal ultrasound and see the yalk sac and a small white dot in the sac and she said its the baby .. I felt so happy . Then i went to another doc to double check and again i saw the yalk sac and the white dot and she said its the baby and she requested a vaginal ultrasound to check more so the tech did the vaginal ultrasound but she said there is no baby !! Im stressed 😔
My hcg went from 802 to 29660 in 10 days but im so scared now cuz Im wondering is it normal?