Just wanted to echo what the other ladies have said really Michelle, early scans seems to be very unreliable at dating. Here's my experience - I had a private reassurance scan at 7+6 which dated me at 7+3 or 7+4 at a push, two days later I had another scan due to spotting which dated me at 8+3 so in two days my little one had done a weeks worth of growing! I'm not sure if it was inaccuracies in the measurements or just that baby had had a growth spurt although I'm thinking the latter because at the first scan baby just looked like a smudge with a flickering hb whereas the second scan you could make out head and body and even tiny leg buds, amazing difference in two days. The later scan agreed more closely with my 12 weeks scan, I was put an extra day ahead at that one. So basically it is possible for baby to start off a bit slow on the growth front then catch up very quickly, I certainly hope this is the case wih your little bean and that you get good news at your next scan. Thinking of you and keeping my fingers crossed for you xxx