Feel confused and really anxious

LMP 29th June

First strong pos 28th July

And I got a 3+ weeks in a clear blue on Aug 7th

I have just been for my early scan, I thought I was eight weeks,going off my LMP, consultant told me that the sack is measuring at 7 and at first couldn't find the fetus, she then said (quote) " there is a little nugget there that is measuring at 6 weeks but can't see a heart beat" she explained that it may be two early for a heart beat and my dates are slightly off or it could be another miscarriage, I had my bloods done as well, she said I may need to go back next week for another scan.

Does this sound bad and I'm in for yet another loss ??

Bloods came back at 57,000 for HCG is anyone able to shed some light?