Empty sac measuring 1mm

Went in for first US and I should be around 6-7 weeks, my sac was empty and measuring 1mm. They took my HGC levels and it was 9,172, I went back 48 hours later and did another test and it’s now 14,000. I am going in for another US next Wednesday. Nurse said to not get my hopes up and it doesn’t look viable but is there any way that I ovulated later and anyone had a similar situation with a good outcome?