Well as far as i know and from experience..ive never had red hairs come out of the calyx's only white and thats how u tell its a female is if it has white pistils coming out of the calyx and you can switch the lights to 12/12 at 4-7 nodes so you can either wait for the plant to mature n show signs of preflower to switch the lights or you can force flower when you want to.And so far from your last two pictures there is some signs of preflower starting but i dont see any white pistils coming out of the calyx so it may be a male but just give it time cuz it still could be a female...never know....But what i would do is put it into flowering.How tall is the plant and how long have you had it in veg?