Sayang, measurements tu memang very individual, setiap baby develop at their own pace! But honestly, you really should ask your doctor or gynae to interpret the scan results, sebab they can see the full picture and compare with your dates properly. A few of my mum friends had slightly different measurements at the same week, but their babies turned out perfectly fine, it's just how ultrasound works lah. Don't worry too much yet; let your healthcare provider guide you on this one!