It amazed me when I here this. I am on my second grow, and just started three new strains one month ago today exactly, oct. 17. I germinated ten seeds. Three were male, seven are female. They all showed sex by the third week. The males all showed sex by the second week at only six inches tall. I have had the same success with my first grow. They all showed sex within a month without me having to flower them. I use a 20/4 light cycle and veg with t5's.
What kind of lights are you using for veg?