Please help so scared.

Hi Iv has to miscarriges  now pregnant again 7 weeks. I had a scan today and they said I was more like 6 weeks. Also I had my hgc taken and was 15522 but all she saw  the scan was a sac no baby the sac was 13mm I feel like I should have seen more with a hgc of over 15000 what do I guys think! Please help as I'm sitting here shaking 😭