Look for 2 white hairs comming out at the internodes in a "V" shape.

If their is balls forming at the internodes its a male.

If there is both then its a hermie, but if a few have got pistilles and a few aint, be patient. They might be taking longer to come though.

Leave it, you'll soon know wheather is a female or male. Give it 2 weeks to be perfect.

If you have pistilles and balls and it is a hermie, cut the balls off and let is flower like a female.