How to tell First sign of flower?

Been looking at my plant and just noticed the first sign of flowering .(yahoo mountain dew).
The little white Calyxes and Stigma,s,one or two of them, then more each day.Looked for info on this and found it.

Well done, thats all female. Its really easy to tell sex when flowers turn up.

Yes it sure is,my thing was finding out when the flower "actually" started.
Not sure if they call this Pre-flower or not but I wanted to find the first sign of the "flower" and seen something on Dr google.
I am still learning heaps on growing.
Soil is at the roots of growing but in Australia it is not good and too expensive to buy from america.
Must learn how to make compost so I can go organic.?