Well I don't have a ton of experience. But on my first grow (12 years ago, lol) I remember the males showed signs b4 the females, i don't know if this is true w/ all strains. & on the other one, well @ 7 days I could see female hairs popping out right @ the nodes, right next to the pediolas (sp? [is that even the right name?]), err anyway, those little things that come out @ the nodes that aren't stems, branches, sun leaves or growth tips... well right around those, white hairs coming out around day 7. & showing on the top most nodes first.