Susah nak predict betul-betul berat baby masa lahir, tapi kalau sekarang 2.8kg at 38 weeks, ada kemungkinan dia gain 200-300g lagi before you deliver, so mungkin around 3.0-3.1kg lah! A few of my mum friends yang scan dekat due date, baby weight estimate mereka off by a few hundred grams jugak, so jangan stress sangat dengan numbers ni. Best thing is just check dengan doctor or midwife your side, they can give you better gauge based on your scan and situation, especially since first baby kan sometimes labour comes earlier or later from expected date.