Welcome to MP. I have a little advise if you are open for it....
My first advise would be to get that mylar straightened out. With that many wrinkles in it, the reflective ability is severely compromised. If you cannot get it to lie flat, toss it and paint your space flat white.
I don't know if it is just the picture, but the first 2 pics look like there is a nutrient/pH issue going on--however I don't see it on the last pic. So are the leaves somewhat mottled and light green or is that just the picture? I ask because I think it is important to have a plant at max health when putting into flowering. We generally wait until we get alternating nodes and/or preflowers before we put plants into flowering.
Part of the decision of when to flower also has to do with your setup and space. I notice that you are using CFLs so you do not want the plant to get too large. Like Rosebud mentioned, we would love to hear about your set-up--size and type of lights, size of space, ventilation, nutrients, temps, ect. That will help us give you better advise on when to flower