veterans please take a look! first time grow

This is my first grow, I have four plants growing under a 400w HPS light. They have been in flowering phase 12/12 for about 5 weeks now. circumstances limit me to the end of the month for this grow. Will I be able to harvest in time? How much longer will it take before I can harvest? When should I start flushing?

One is a grand daddy purp and the other three are unknown.

also, any ideas on what strands I have?

Any help, advise on anything is much appreciated. Thank you!

the first two pictures are of what i think is my sativa plant. the second two pictures are of my much smaller granddaddypurp.

the first two pictures are from one plant and the second two pictures are from another plant.

also, can anyone tell me approximately how much i will yield from this harvest?

hard for ii to tell..

they loo good tho...keep beeing kind to ure kin!!!!!!!!!!!

the purp you could probably harvest soon but you'll have to wait on the others.

can you tell me in weeks?