Sweeeeet! I'm glad you posted this thread, man. I actually was just about to start one but you seem like the guy to ask anyways.
I still have my plants in veg, this one has had about six weeks from seed but it had 2 weeks with conditions where it basically didn't grow at all, so it basically looks like a four week plant but is starting to alternate leaves where its a little older. At first I was thinking it was starting to show sex already (aren't they suppose to show sex a couple weeks into flower?) But now its looking like its just another part of the branch structure.
My kittens thought my plants were a toy and shredded a couple of the leaves. Anyways, so since the sex parts show up at bud sites, and buds start to develop up top first, I'm assuming that when they start showing sex, that's the first part that they show it? At the top of the plant?