Eccles - hmm...will have a go...and this will be jumbled, but there are heaps of books out there about connecting with the power of menstruation, so read one of those if I make no sense at all 
So, it's no coincidence that our cycles are, on average, 28 days long, and it's thought that, if we lived more in tune with nature, our cycles would match with the lunar cycles...and, of course, each others. We are mostly made up of water, and the moon has huge effects on water.
However, when we disconnect from that, as we have been persuaded to do by the patriarchy for a good couple of thousand years - being told that we are impure or dangerous when we're menstruating, that menstruating women can kill newborns just by holding them, that we go mad when we menstruate etc. - we miss out on a powerful awareness of how our cycles really work.
We are so conditioned to live statically - the same day by day - and we don't honour the fact that we do actually have changed emotional states, abilities, and even states of consciousness throughout the month...hence PMT.
When we're coming up to our periods, we're naturally more creative, more in tune with our subconsciousness, and we don't put up with things we normally put up with - but instead of seeing that as a gift - a chance to see what problems there really are in our lives, we see it (thanks to the patriarchy) as a curse.
When they did studies to see how productive women were in the workplace, thanks to menstruating, they found that men's moods changed just as dramatically as women's, but that women had the benefit of being able to predict their changing moods.
Imagine if we lived in a world where women retired from life once a month, to dream and meditate on their lives, on problems, on society, to make plans, to rest, and to be creative, together...and then were super-productive and super-respected the rest of the month?
This is how we used to live, when we had matriarchal societies, and before power became the issue it has been for the last couple of hundred years. Now menstruation is something to hide, and to be ashamed of. It's something to ridicule, not to celebrate.
Does any of that make sense?
Hello TBE
Was thinking of you all while I was watching this film and thinking 'Yes, Yes, Yes!'
All feminists should see this - so enlightening! Difficult to find out where its being screened though - look up The Women's Quest and see if there's any groups or anything local to you.