I have had several m/c's too, but no longer trust early scans. I had scan at 7w3d with my dd where I was told there was nothing in the sac and I would m/c, clearly I did not as she is now a healthy 7 year old. I have also had scans where we have seen the heartbeat only for it to no longer be there two weeks later.
Last pregnancy 6 months ago, I was told I had not miscarried, but things did not look good as I was measuring 6 rather than 8 weeks, and two hours later same hospital scan showed I had "lost everything and uterus was normal non-pregnant size" etc. (nothing happened in that two hours, no bleeding or anything). I stopped all my meds, my levels slowly decreased and 4 weeks later I was very shocked when I passed the pregnancy sac (about 8 week size). So I had stopped the meds and even now don't know if it was stopping the meds or a natural m/c.
I am currently 7.5weeks pregnant and not even gone to doctors to tell them I am pregnant again. I do not intend having any early scans this time, I can't trust the sonographers.
Early scans can be very unreliable, especially if you have a tilted uterus, as you can measure 2 weeks behind and stress is added if you have a poorly performed scan is horrible.
One funny story I have of an early scan: when I went to an early pregnancy unit and was scanned by a junior doctor, she was measuring my ovary, I thought this was strange and even stranger when she started telling me that the pregnancy sac was empty and she was going to get the consultant. The consultant quickly found the real pregnancy sac, at the same time, the junior doctor discreetly binned her printed pictures of my "empty pregnancy sac", I guess that is a lesson she will never forget. 
In my opinion early scans at worst - cause more stress, and at best - provide only a brief period of reassurance. But for some women those brief periods of reassurance help keep the overall calm of those stressful first few weeks. Regular reassurance, has been proven to be good for the pregnancy and one of the few things proven to help in recurrent miscarriage!
Sorry this is so long, in summary: I think each women has to decide for themselves whether the early scan will help or not!