Period, time of the month, a visit from Aunt Flo, a crimson tide, or just plain menstruation - whatever you call it, you’re probably not talking about it, says Sarah Simons, as she asks, why are periods still such a taboo subject?

Of course, there’s the blood. And blood can be scary, and the sight of it can trigger dizziness, vomiting and fainting. But, there’s horror film blood, and then there’s practical blood - for things such as life-saving transfusions, which have only hopeful, grateful emotions attached to them. Quite unlike period blood, then, which is met with not just a drip, but a flood of disgust.

For the half of the population who will never experience menstruation, this regular physical event might be considered alien in the extreme, says Simons. Vaginas are both the place of sex and babies - when you throw periods into the mix, it can become a bit too bamboozling for some blokes to manage. For them, it’s easier to pretend periods don’t exist.

It’s culturally understood, by both men and women, that a woman’s “time of the month” must be kept under wraps. Why? For women, says Simons, it’s a deeply internalised feeling of shame.

She doesn’t suggest that women should march into every conversation booming that their flow is flooding, boobs are banging, and that they have a desperate urge to thump anybody who irritates them. Instead, she champions the need to be heard; the ability to speak up, without shame, and only if women choose too, and say, actually, “I feel pretty bloody awful.”