My mother sat me down and told me in detail about periods and pregnancy when I was nine or ten.
Before that I had seen her packets of sanitary towels in the bathroom cupboard and asked what they were. She replied then that grown women had "periods" that caused bleeding once a month, as it came from the womb, and was all part of being able to have children. At that time, she warned me not to mention it to girls at school, as a lot of parents thought children should not know about such things. She also said, she and my father thought that silly, as it is perfectly natural.
I was coming up for thirteen when I had my first period - but for most of the preceeding year I had noticed that once a month my underpants were stained a dirty yellow colour in the course of three or four hours and stank of ammonia.
This was presumed by my doctor father to be a part of puberty, although he admitted he had not encountered it before, but said he assumed that was because mothers of girls my age "didn't think it was nice to discuss it with the doctor".
I imagine he was right about that.
My periods were always very heavy - no surprise there as my mother's were too.
Tampons were "only for married women", not that I would have been able to use one before loosing my virginity, when I remember the pain of that particular happening!
I did use tampons later on, unsuccessfully as no tampon could last more than twenty minutes so they were always reinforced by sanitary towels, a dancer's belt and black underpants!
There is some justice in this world - neither puberty, nor the child-bearing years were fun from the biological point of view, but the menopause was a breeze. My periods stopped shortly after my 50th birthday - no hot flushes or other unpleasantness.