I have 4 Hamburg girls who started laying after all the other breeds, probably 25 weeks or so. Then, we went through at least another month having to search for little white eggs everywhere. Twice found big nests full of 12+ eggs in the woods. Realized they were so timid with the other pullets that they were not being allowed into nest boxes, even though there were plenty. I went around the farm making ad-hoc nests in little nooks & crannies, straw bales, etc and put fake eggs in. The hamburgs managed to find the semi-hidden nests and started laying there. Eventually, they started laying in regular nest boxes in the coop, for a few weeks of easy collecting lots of eggs. Now, 3 of 4 have stopped laying to molt, and I think the other is not far behind.