Migraines. Defo related to my period even though the doc says it's nothing to do with it.
Also, javelin arse yes! (makes me laugh that saying, even though the thing itself doesn't make me laugh!!!)
Hideous cramps (obvs!)
Sore chuff bits (and the 'periody' smell!)
The way the blood has phases of gushing out (past tampon AND sanitary towel!)
I have had to run to the loo in public many times, to 'clean up' and had a massive heavy uncontrollable flow on a 10 hour coach trip once. Vile. 
The mahoosive blood clots the size of a cow are fucking putrid. What is THAT about?
I mean, just why.....
And yep, sometimes the period poops. 
Greasy hair and zitty face.
Oh and when you have a poo, the clots being forced out of your foof!
Grizzly mood and feeling low and tearful for 3- 4 days of the month.
Having a trip or holiday or special event blighted and marred if the monthly curse pops up during it!
Ewwwww, who would be a woman eh? 
I have had periods for over 30 years now, and I have never ever ever got used to it. Most things in life you get used to over time, but periods? Never ever ever. You NEVER get used to them. They are actually vile. There is nothing good about them. NOTHING. 
God is obviously a man. A female GOD would never have cursed women with this living hell. 
I love this thread. Thanks OP!