Baby weight at 31 weeks varies quite a bit, some babies are 1.8kg, some are 2.3kg, so 2kg is actually within the normal range, alang-alang nak tengok growth pattern je at 34 weeks. A few of us at playgroup had similar scans and doctor kata yang penting is that baby's growing consistently and on track, so don't worry lah, tunggu next scan nanti confirm everything is good!