makes perfect sense to hold off on the u/s - i think i only got one so early because of the fact that it was an IUI pregnancy and they were checking viability, number of sacs, and that it was in the right place. i had another scan at 8w3d and the FS requested an internal scan as it's clearer. don't be afraid if, when you get to scan, to ask for an internal scan if they say they can't see enough - i know it's not comfy, but it's comforting when you can see so much more