Take a chill pill, wait until you can actually see what they are and no doubt you'll be able to decipher them as there is a billion references as to what a male and female pre flower look like for comparison. It's one of the easiest, most apparent parts of growing.
99% of the time newbies are trying to decipher pre flowers far before they have even appeared for no reason bar anxiety. It's the only reason most of them can't sex the plant properly. If they waited another three or four days before trying it would become pretty apparent naturally.
TLDR, no need to be in such a rush to sex the plant. It will become glaringly obvious in its own time, and saves all the speculation.
If you can't sex them after a week or so if showing, help will be required, but they will show stigma within a few days of appearing if female, and won't if they are male.