one female clone and one unknown

i have two plants currently in the veg stage. i have one misty plant that is a female clone. the other is a big bud in which i started from seedling. i am trying to find out whether my big bud plant is a female or a male. what should i do? i do not feel like switching my whole op to flowering just to find out. is there any other way i can find out? i heard that if i took a clone from the big bud and flower it i could find out the sex. but i never tried it. has anyone have? if so how long does it take?

I would lst the plant to get lots of branching, then take a few clones. It should take 1-2 weeks for the clones to root. In a separate chamber put the clones under 12/12 lights. 1-3 weeks later it will show sex.

Also you can just veg the plant until it shows sexual maturity and shows preflowers but this will probably take awhile.