Nice to meet you too!
It's a mystery to me. After losing our last little man I tested positive to the blood clotting disorder but the follow up test was negative. I asked if it where possible that I only have this disorder while pregnant - but apparently not. Sounds strange but I had privately hoped I did have it because then I could be monitored and tested in future (fingers crossed) pregnancies. And it could have provided some much needed answers to why?
Did your sac continue to get bigger? Mine got slightly bigger and closer to what was they healthy baby....my DH used to joke it was a red wine sac...because my body missed it so much...