Littlepolly I'm thinking of you in everything you're going through at the moment. You must do what is right for you but I agree with others who have mentioned how traumatic a medically managed miscarriage can be, be kind to yourself whatever you decide.
Sparkly please don't worry at all about your scan - a gestational and yolk sac in the right place is good news for 5+6 weeks, and sometimes I think sonographers are unaware of their power to strike the fear of god into our hearts! So much changes day to day at this early stage it's really hard to say for sure whether you're 'too small' or whatever. Take comfort in the fact that everything was there that should be and in the right place. I had a scan at 5+6 that showed exactly the same thing, then after a heavy bleed (convinced I had lost it) had another scan at 8+3 and there was mini-monkey's heart beating away. Try and think positive.
Talking of positive - I had my dreaded nuchal scan yesterday afternoon and everything was perfect! I was so nervous in the morning I was crying and wailing like a banshee, by the time I got to the hospital I was convinced I'd had a MMC. But no, this time I'm lucky, and there was our baby dancing around, doing back-flips and giving us a little wave! Obviously a monster show-off already
Most importantly (I'm 37) my trisomy results from the scan and blood tests were great, so that's one hurdle over with. They're still classing me as a 'high risk' pregnancy but I'm trying not to dwell on that too much, now just basking in the lovely glow of a good scan and trying not to focus too much on the next one. That will be the big one for me, a fetal heart scan at 18 weeks.
But for now, as someone who has had 2 MCs at 5/6 weeks and lost a baby to a heart defect at 24 weeks, I'm just thrilled to have seen an active (hopefully) healthy baby on that screen