You are at pretty much the same stage as me, it was 7 weeks yesterday for ours and we're estimating another 2 weeks. Pics in link in sig if you wanna look, there's recent ones on the last page, I can never copy them across very well! Mine look to have a little more yellowing than yours, which worries me a bit cos if they're that hungry that they're eating themselves while I'm still feeding them then they're gonna be hungry when I stop, and it doesn't feel right to let them go hungry (I know I just way over-simplified that) even though I know it's natural for them to cannibalize themselves a bit before harvest.