Showing Sex at 4 Weeks?? Light Test

I have pre-flowers showing if not female already on my first cabinet grow and wondering if this is normal,
Plants are only 4 weeks old today (killer bag seed); I tried an experiment to see if I could increase bushiness and lower growth
(a plant will grow thicker if getting light from underneath theory of mine)
I did this by placing mirrors under 2 of 4 plants; the 2 plants that had mirrors are 7-8 inches tall and very, very bushy
With large amounts of lower growth, the plants without mirrors are 4-5 inches with normal growth; I also noticed the 2 plants with
Mirrors are both showing what appears to be female pre-flowers (pistils without balls?) and contain white hairs, I have been on 24
Hour light cycle and a few days of 16/8 cycle to encourage root growth (read this somewhere) I now am on straight 16/8 cycle,
I am feeding/watering every 3 days or when soil is dry to touch 1 inch down, the nuteâ??s Iâ??m using is MG 24-8-16, lights are
4 6500K 100 watt CFLâ??s placed 3 inches from topâ??s, air temp is constant 85-88 with 15 degree swing when lights are off.
Just wondering how long I should wait to start 12/12 light cycle.
This is my first real attempt at growing real BUDS so a little confused, as soon as I can figure out how to get new cam in Macro will post picâ??s
So you all can see these â??Light from both side babiesâ?