Eh normal je, especially if scan pertama tu awal2 pregnancy lagi, margin of error dia lebih besar, so scan yang lebih dekat ni usually lebih accurate sebab baby dah besar sikit dan easier to measure. A few of my mum friends experienced the same thing, especially those yang scan awal-awal, and doctor dia cakap it's nothing to worry about, just recalculate based on the latest scan je. Tapi kalau you're still worried or ada other concerns, best to ask your doctor directly pasal they know your full history!