I had more positive ICs today and positive Superdrug Early. Doctor explained the blobby thing I had was probably a partial decidual cast, or decidual bleed. The difference being as far as I can gather, a complete decidual cast is where the lining keeps growing until there isn't any room left and it's expelled which causes a lot of pain and bleeding, which I didn't have. But apparently although the blob is more unusual to see, a decidual bleed isn't unusual early on. Going to ask for betas anyway