Viability scan, 6 weeks (IVF) - miscarriage

Hi all 

I had a fresh transfer of a 5 day blastocyst on 24th April (my 4th transfer, 2nd cycle), I got a BFP and the line on the test continued to get darker throughout the 2 weeks before my scan today (6 weeks 1 day).  There was a 'beautiful' embryo sac but no yolk sac or heart beat 😢. I have been told that I need to return for another scan in a week or two - why? I'd much rather stop the pessaries and start the process of the miscarriage so that I can move forward.  Everything I have read (and speaking to the clinic) it is highly unlikely there'll be a positive outcome from this next scan - so I just don't see the point in it or continuing my medication.  Has anyone else experienced this? TIA x