There is no need to freak out. Scans are useless for measuring babies unless they are repeatedly done to measure the growth of the same baby. If you take the population as a whole some of us will be tall and some small and that is all your ultrasound has told you that your baby is not on the tall side. If you look at yourself and your partner I'll bet you aren't either. What the ultrasonographers measure is a bunch of predetermined things like head circumference, abdominal circumference, femur length etc and then plot your baby on a graph for the number of weeks you are. 50% of babies will be below the 50th percentile and 50% will be above it (thats what it means) correspondingly 10% will be below the 10th percentile and 90% above it and 10% will be above the 90th percentile and 90% below it. The trouble is that they then compare your babies measurements to the 50th percentile and tell you its small for dates. Its not small for dates its just not as big as a baby who would fall on the 50th percentile. 'IF' you agree to another scan if four weeks your baby will still be exactly the same because even if its grown appropriately for four weeks it will still be below the average. You dont need another scan because any caregiver, midwife or Obs worth their fee will be able to tell if your baby is growing simply by feeling your fundus and whether it is increasing appropriately from one visit to the next. Thats why we do it. So chill and enjoy your pregnancy.