Sexing question

So, I am aware that some genetics will refuse to show sex until the lights have been flipped to 12/12. I am only on my 4th grow atm so I haven't come across enough males to understand exactly how they present themselves and if certain strains show male pre flowers differently... I have 3 females showing pistils and one pure sativa that has been showing pre flowers for 2 weeks on every node that look almost EXACTLY like a calyx, (typical bulb on bottom that comes to a point) but not a single pistil has emerged..

Is it normal for some sativa strains to show calyx without pistils until flower? Or am I looking at a male that needs to be culled? I have a male WW that is very easily identified but my pure sativa is playing games with me.. I've seen plants wait to show flowers but never seen preflowers refuse to show pistils..

If anyone could shed some light on the subject It'd be much appreciated.. Anyone with pictures of any and all male preflowers they have come across are welcome too. (just preflowers, as I can easily spot a pollen sack) I'd like to broaden my database in order to more promptly deal with males so I can replace them with my cloned females!

I dont have time to upload the 290,000 pictures from my first google search
check it out

here

Thanks but as I said, I don't need pics of pollen sacks. It's very easy to Google and get a million pics of the same thing. Not every plant grows the same. Most males I've seen show preflowers that don't look uniform across other males. Looking for input not a Google search.