I'm so sorry for what you're going through! I know how tough it is - this seems really similar to what I went through. My first beta was a whopping 48 and it continued to barely double. By 7 weeks it was only 7800 and my doctor had similar concerns. I am happy to report that I am now 18 weeks pregnant and all is well!

I'm keeping my fingers crossed for you, OP! Good luck.