It's maybe because the pic is too small but that plant does not look mature enough to be able to decern it's sex yet. This is only from what I can make out in your exceedingly small picture. Try and post it again larger and we will do our best to help you out. Happy smoking.
You will haft to wait a little longer it takes 7 to 21 days to show sex in there some were give or take a few days some strains are faster then other in showing sex you have it in 12/12 right....?
Hope this helps you a little...