Ahhh, I'm so sorry about your first pregnancy, but congrats on baby number 2! A few of my mum friends juga pernah kena kantung baby slightly bigger than expected, and honestly, it bisa jadi timing issue lang, sometimes dating scan tu tidak 100% accurate, especially if cycle kamu irregular or implantation agak late. But since doc dah mention it, I'd really suggest follow up with your doctor or specialist to check if everything else okay (baby's heart, measurements lain-lain) sebab they can give you yang most accurate picture based on scans kamu; better to get peace of mind daripada stress alone, kan?