Nope definately not at 20 weeks.

I had to have a scan after a fall at 35 weeks recently & they said at the time of the scan he was approx. 2.5kg or 6lbs.

Friend of mine had herself all freaked out with her last bub coz they told her she was going to be BIG. Got induced 3 weeks early & found out she would've had a normal sized bub anyway.

Sizing seems to be VERY subjective.