This is my Red Sex link hen, she just started laying last Saturday at 16 1/2 weeks and this pic was taken last week, so right around the time she layed.
She had started squatting when I would pet her about 3 weeks before. I knew the day she was gonna lay, cuz she got frantic, ran the fence (she never does that), cried a different sound, and actually begawked and clucked, and that was the first (and only) cluck I have heard from her, the first two days she layed. Also, her behind looked fuller and rounder about 3 days ahead of it. I commented to hubby an family that she was lookin full around the hiney and was about ready to lay I thought, and sure enuff, two days later....
This is a before picture...you will notice also the first picture, right at point of lay, she stands with her chest stuck out more now. Like she is a proud lady, she never did that before...this was before...see the dif in how she stands with her chest...
In my case, I could tell more by her back end, instead of the comb/face. She got red several weeks ahead of time...this pic was taken the night before she layed her egg, so you might see what I mean, she looks a bit like a lady with bloomers. lol
her face...no indication for me...
Hope this helps a bit...you have to pay REAL close attention to your chickens in order to notice it.
Jill