Hmm. Need small correction here. Flipping 12/12 may speed up sex signs to show up. You’ll see small preflowers soon, even if the light schedule is not 12/12. Then you’ll notice the branching is changing from symmetrical to asymmetrical. That’s the sign the plant is ready to flower. Yes, no real flowers can be seen until flipping 12/12, but preflowers will be there 100%. They can be very small, but pistils should be visible. Male plants usually show sex earlier than females. You’re on 5th week of veg, and no male signs yet? Most likely it’s a female.
But actually you don’t need to guess if it’s male or female ;) just click on your strain and you’ll see its Feminized photo. 99,99% it’s a lady.