Yeah, and remember that the u/s are quite inaccurate. I was told 2 days before my DD2 was born that she would be 10lb 11oz, and she was 8lb 13oz.. no where near the same weight. They measure the bones in the leg to make a weight estimate.... so maybe your baby is just tall like mine

With her, she was in 0000 for 1 week and then into some of the 000 I had.