You're plants look very healthy, bro! Flowering time really varies. Mostly, it's between 8 - how ever many more weeks until your trichs turn milky and your pistils start to turn dark orange. You can harvest different parts of the plant at different times during the last stages of flowering to get a different feeling from the bud. For instance, if you want a bud that is a stoney, get up and do it high, harvest some bud a little earlier. If you want a straight couch lock feeling, then you gotta wait till the very end of the cycle. Of course, don't wait too long or you will miss your window of time and really lower the potency.
I hope my info was correct... If anyone else has something to add or correct, then do it! Help the man out!