Good luck Bec, it will be over soon and then you can have those cookies!
Lch, I think 4,2 at 31 weeks is probably a little big but not very...Munchkin was estimated around 5 lb at 34 weeks (I can't remember how big exactly...5 lb 3 oz I think? It's probably in this thread somewhere) and that was very close to average, and he was born 7,6 over seven weeks later. The u/s can be off in either direction, but you are on track to be somewhere around 5 1/2 lb by 34 weeks I think, so not that much bigger.
Nope...he is starting to wear 6-9s and 6-12s now, though they are long on him...NB was perfect when he was born but it lasted about 2-3 weeks. Fortunately most of it was hand me downs. 0-3 was another few weeks, and I think he was in 3-6s by 6 weeks, until about now. He grew REALLY fast though...doubled his weight by 2 1/2 months (usually 4-6 months) and now I think he is the size of an average 6-7 month old. So not everyone will go through sizes that fast...
he is like that today in a new 9 month coverall. The problem is that he likes sitting so much now that they bunch up under his chin if they are too long in the torso. And then he chews on the excess fabric and there is spit absolutely everywhere. 
