W top or borrom of plant to identify m/f

Hey guys, day 7 of flowering, all is well, started with 4 ogiesel fem seeds, plants are healthy, my question is should i be looking for first signs near top,or bottom of plant? Is it normal to buy fem seeds and they end up male?
Thx.

its not normal to have pure males in fem seeds, i usually look closer to the top or middle range

I usually see signs of sex around the 4th or 5th node down from top of plant..
And no, fem seeds should mean female plants.. I've never had a male from fem'ed beans before..

Thanks guys