you don't want to flower for some time i would say. They need to grow during the vegetative stage for some time yet before theyll flower. You can force them to flower by putting them onto 12/12 but your yield won't be great and the quality will probably not be as great. i would wait until theyre a substantial size bigger. If you leave them on 18/6 light hours then the plants will show u when theyre ready to flower. Little pistils will form at the stem and you can determine the sex, your should all be female but check anyways as you can sometime get a hemaphrodite plant and that could take ur whole crop down. Be patient with it, enjoy growing it and you'll get an amazing end result, if your not patient with it then your end product will reflect the way you grew it. Your plants are looking healthy so look after them and they'll reward you lol. Good job dude.

Cheers

Bob