Good question, but a bit odd....
It has been my experience....
Seeds take 12-25 days to form ...
Buds must be only 7-10 days old to gather pollen...
My plant only exposed to pollen with a 5 day old pre bud... did not get seeded...
------------hope this helps.......
Why not, try and take a clone or two, small bottom branch...
Then once clone is going sex it by putting it into bud...
Then you have two plants if it is a fe-male, and no re-vegg?
Re-veg will give you weird growth, and stall out [stress] you plant to the max...
Good Luck either way...