we can be so geeky sometimes huh?? lol...some people looked at me like I was weird cause I was so excited about my first eggs lol. like a kid in a candy store!!
As for your question it al depends on your chickens, but mine...the first week the eggs were about a small, the following week they were medium and by the third week they were large. I have some chickens that lay xl eggs and they are some beautiful eggs too.
so I would think, that within the month they will reach their normal average size of egg.
My very first eggs I had from my girls were hard boiled, both my younger son and my dh never ate eggs because they had a bad reaction from them. since getting chickens and trying the first free range, farm fresh egg they have not any stomach issues at all. that right then and there told me I had made the right choice in pursuing chicken keeping.
Ema