Baby size.

I am a FTM due soon, i had one last appointment with my high risk specialist who takes measurements of baby at every appointment. 3 weeks ago they said baby was around 5lbs 3oz and now they say she is 8lbs exactly. Was this accurate for any of you? Im very concerned with her weight being that there is a week to 2 weeks left. And i have a lot of newborn clothes(hand me downs) and dont want her to be too big for them.. How long did your baby last in newborn.?