Oh love, if you got a positive test on the 28th November, and your last period was 31st Oct realistically that would place you around the 9 week mark by now.....eight and a half at your last scan, or 8 at the very very earliest.
I know the hospital say by their calculations you should have been 7 at the last scan, but they were only basing this on the fact that two weeks earlier it measured 5 weeks (when your dates suggested you were already 7)- their dating isn't a real reflection of the dates involved if that makes sense.
For the baby to only measure 5 weeks now because it is healthy but early days, you would not have got a positive test for another three weeks or a month after you did.
I just don't think there is any way that the dates can be that out. I'm sorry. And as I said before, for me if there is absolutely no growth between 2 scans then it doesn't have a good outcome for me.
I second what bakingtins said about setting yourself a time limit for how long you can wait it out before going for another option.
I had a ERPC at 11+6 for a baby that had stopped at 6+2......by that time I was still showing no signs of MC naturally, and I just got to the point where I couldn't take the torture of waiting any longer. I'm really sad that you are having to go through it too.