I have been horrified to find out there are young women out there that have absolutely no clue about their menstrual cycle. I mean none. If I were a female I would want to know damn well when I was going to start bleeding from my crotch. I assume, probably correctly so, that these clueless women are the very same ones that demand abortions on demand.
There is an episode in the second season of “Orange is the New Black” between some of the women prisoners about where urine comes from in a female.......some of it was pretty funny, but it confirms your suspicions.
It’s not just that some have no clue though.
As the article points out, some women have irregular cycles.
My wife has had cycles just over two weeks apart. She has also had cycles four months apart.
I think there would still have to be either a reason why the baby didn’t kick or a reason why the woman didn’t feel the kicks for even an obese woman to be unaware.