High HCG level & no embryo

KC • Heaven has another angel. November 11th will always have a special place in our hearts.
Yesterday I had my blood drawn and my numbers came back at 43,000. I also had an ultrasound and the tech were only able to see a gastational sac and no embryo. Based on the first day of my last menstrual cycle which is May 9th I should be 6 weeks and 6 days. However I know I ovulate late which is day 18 and my husband and I had intercourse on May 24 & May 26.
If I am early, does my HCG level make sense? I feel that's a little high...