I am normally quite a rational woman.

No really, I am.

But for a few days each month, I transform into someone I hardly recognise.

I become irrational, cannot think straight and interact with the world in an entirely strange way.

Men try to understand what it is like to be a woman experiencing menstruation, they attempt to be sympathetic and supportive and unjudgmental (and I love them for trying).

But they do not truly understand why or how the transformation that happens in the woman they know, or love, takes place.

Let me try to explain what it is like.

7 days before my period: I become crazily horny. Not just your normal, "ooh I really fancy a hard cock inside me fucking me hard" kind of horny. No. Nothing like that at all. You know when you are so craven for sex that you look through your phone book, see the name of an ex you haven't spoken to for 5 years, who wasn't even that good in bed, and you consider calling them to ask for a quick shag for 'old times sake'? Well times that by 100.

I'm talking so fucking horny that you do call them. And try to go over there to get some sex. And if/when you do get a shag, you are so craven that you leave marks on their body.
I'm talking so fucking horny that when you've just finished climaxing from one frig, your clit starts throbbing and you're already halfway into the next frig.
I'm talking so fucking horny that you run out of AA batteries. Three times.
I'm talking so fucking horny that your vibrator breaks from too frequent use.
I'm talking so fucking horny that there's no point wearing underwear, since it ends up permanently wet.
I'm talking so fucking horny that everything you do, think or say has a connection to sex: chopping up a courgette for dinner warrants a quick wank; listening to a good song on your ipod warrants a nifty frig; seeing a cute man walk down the street warrants a speedy fiddle. Everything seems connected to sex.

4 days before my period I become emotional: I get upset at the smallest things and find myself weeping uncontrollably.

I get upset about an advert featuring cute animals on tv. I have been known to cry at Andrex commercials - the very same ones that I switch off in disgust at any other time, feeling that my intelligence has been insulted by the patheticness and cheesiness that they portray.
I get upset because I have to wait in line too long at the supermarket.
I get upset about all the injustice in the world.
I get upset by people that bump into me on the street.
I get upset that I have not 'made it' in life yet.
I get upset that I am single and lonely and obviously unlovable and will end up being a spinster.

3 days before my period I become angry: I experience fury at the smallest things and find myself swearing out loud and wanting to fight anyone who approaches me.

I get angry that the bus driver pulls off without waiting for the elderly person to find a seat.
I get angry that the line at the supermarket is too long.
I get angry that the tube gets stuck in a tunnel for half an hour and the driver doesn't tell us why. And there is no air conditioning. And the man next to me smells of BO. And my ipod batteries are flat.
I get angry that I voted Labour in 1997 to get the Tories out, knowing that Blair and his cohorts would betray their promises, but hoping that they might still invoke some change.
I get angry by people who bump into me in the street and don't say "sorry".
I get angry with myself for being such a fucking procrastinator and not getting my head down to make the changes in my life I need to make to be happier.
I get angry with myself for always resorting to masturbation as a way of avoiding getting my head down.

2 days before my period I get back pain. Like how you feel when you've been standing for hours; your lower back aches and feels tender. My breasts swell. They no longer fit into my bras. They are heavy, painful and tender to touch. They ache when I walk. My skin breaks out. I look like a teenager with hormonal spots. They are painful and unappealing to look at. My hair becomes greasy. Where once I had lush locks, it then turns stringy, shiny and lank. My abdomen swells. No amount of 'sucking it in' makes it lie flat. I look 3 months pregnant. I don't recognise my body - it doesn't feel like 'me'. I get crazy food cravings:

Protein: cheese, red meat (as rare as possible), spinach, nuts.
Chocolate: 70% cocoa dark chocolate
Alcohol: red wine.

1 day before my period I feel sick. Vomiting seems moments away. Nausea strikes randomly and often. I feel faint. Passing out seems too close for comfort. I grab hold of things to stop myself falling over. My stomach hurts. It feels tender and swollen and throbs with a dull, deep pain.

Day 0: the pain begins, steadily. It feels like someone has a knife in my abdomen and is tugging away at my insides. I feel dizzy from its intensity. My pussy feels like it has been kicked. Hard. The pain, though it is ever present, comes in waves, contractions, cramps. Everything clenches up into a tight knot, twisting, turning, tugging, burning. It makes me retch and gag. I pull myself out of bed to put something in my stomach so that I may then take some painkillers: 3 Ibruprofen, 2 paracetamol, 1 tab of codeine (I know the daily and combined limits of each). They take over an hour to kick in, an hour of agony lying still and waiting. And when they do, the pain is still present, but the edge has been taken off it. In comparison it is bliss: I feel human again. But the downside of the painkillers is the drowsiness: yes, they mean I can stand up (and work if I have to), but they slow my brain down, make me want to lie down and sleep, not conducive to a day on a film set.

Day 0: the bleeding starts. It makes me feel weak, nauseated, fragile. It always looks more and worse than it is, I'm sure. But every month, I look down at the tampon or pad, and think, "jesus that's a lot of blood coming out of me". I know this is what makes me a woman, but I resent the incapacity of this, the amount of bloodloss, the needing to visit the toilet frequently. In the man's world of movies I work in, having to change a tampon every hour or so, doesn't quite fit in with the need to be on set all the time, and fighting off the comments I get as a result of this angers me.

Day 0: I lose my sex drive. I know, surprising. Me, the Girl with the one-track mind and all. But with agonising pain in my belly and back, tender breasts, and heavy bleeding, it would take a lot for me to be in the mood. That isn't to say I can't be convinced (and I have), but the thought of sex is far from my mind. Instead I am counting down the minutes and hours till my next intake of painkillers: a true addict to the drugs.

Day +1: I get my sex drive back. Having a quick frig whilst increasing the blood flow (post orgasm), actually ends up lessening the pain. There is a direct correlation between the amount of orgasms I have and the amount of pain I am in: more climaxes = fewer cramps. So I end up fiddling as much as possible. The bloodloss is now manageable, the pain is slightly less, and I feel more rational. I can think straight, am not beating myself up for things I haven't yet achieved, and feel positively happy about still being single.

Day +2: I feel distinctly sexy. Womanly. Vivacious. My confidence reappears, my body seems more familiar to me, my sex drive seems normal again. I have regained myself and feel happy once more. Life can continue as normal.

And after 4 or so more days, I return to just being The Girl and the monthly cycle begins once more.

It's weird to become this different person for a few days each month. I hate it: feeling even more a slave to my hormones than I normally am. Plus, it takes a good friend or lover to understand and be compassionate about the mood swings that can accompany this process.

I am not trying in this post to justify someone being a bitch, just because they might be menstruating at the time, but I am attempting to shed some light on why some women might be perceived as acting out of character occasionally, with no obvious provocation. A little understanding and compassion about this can go a long way.

As does regular orgasms. If more men realised that by giving their partner an orgasm (or 5), whilst she is menstruating, then,

a) she'd be in less pain
b) she'd be in a better mood (with them)
c) she'd then be more receptive to a good shag

I reckon they'd be happier too. It's worth a try right?