hi there. is my first grow and everything is fine until now

but i have one AUTO THC BOMB and on the seller website it tells it will take 60 day from seed to harvest. my plant is in the 69 day now and i dont know if is ready to harvest or not. from all plants this is the only one with loose buds, i dont know why because the conditions are almost perfect, but maybe is the genetic. some buds have many brown pistils but a lot of buds are still have white pistils. i will post some pictures here with the plant and the trichomes and i wait some suggestions

. thank you very much in advance.
in the 3th picture are some buds from under the plant and in the last picture i took a shot of the bud (it is very loose)
so when you guys think is time to harvest for this plant?
sorry for my bad english.