Extremely worried…please help! Also TW: Possible loss

Hi everyone. I was just wondering if someone had any experiences like this or advice. Please be completely honest as l've had 8 losses already and would rather someone be straightforward with me as doctors are avoiding my questions and concerns.

So I was in the hospital 10 days ago at 6 weeks + 4 days, with some pain, no bleeding, but measured 5wks+6days. They brought me back today, I should be 8 weeks exactly. But could only see a tiny fetal pole measuring at 6+1 with a very slow flickering heartbeat on the screen, they couldn't pick up heartbeat to hear. They checked my pulse also to be sure it wasn't because of mine that baby's heartbeat was so slow and mine was fine. So i pretty much only had 2 days growth in 10 days?

They want to bring me back in another 10 but l feel like I'm heading towards another loss. I should add that I got my first positive pregnancy test December 14 so I couldn't be that much off with my dating, definitely not by two weeks it just wouldn't make sense I wouldn't have gotten any positives when I did? Thank you.