I agree with everyone else hun, you can do this dont opt for a c-sec cause if scans
I myself havent experienced this but my last scan showed bub to be 2.5kgs he was born 2.2kgs they can also vary dramatically in size
your best bet get your midwife to feel your tummy and estimate, I dont know if anyone else has had this happen but with DS1 I had a midwufe feel my tummy and estimate a 3.5kg baby and he was born weighing 3.6kgs

whatever you choose hunny goodluck and I cant wait to post your BA!