Need advice!

Tested positive on digital test Aug. 10. Hcg was 662 on Aug 16. Last period began July 1. (My cycles are 37 or more days long) Hcg was 6286 on August 29. Went for ultrasound today (abdominal and vaginal) and no Sac was visible - she said all other signs show I’m pregnant - thickened lining, etc. Was told my obgyn and radiologist would contact me in morning...

Anybody else have this with a positive outcome?