m0useanswered grow question 10 months ago Plants will show their sex if they are left in Veg long enough I tend to see this on week 5 or 7 in veg.
Given this is on day 28 or week 4, it very well could be an autoflower or just showing its sex on a photoperiod. If you don't know the lineage of the seeds or their genetics before growing them then its a coin toss in figuring out what they are.
Good Luck!