Period Cramps should be taken as a valid reason to be absent. Girls have different levels of pain tolerance when it comes to this, and having to show up to school or to work can awfully be too much stress for us - and that's just the physical pain we're talking about...
I donโt like arguing. I just want to be understood, and invalidating my feelings frustrates me. This is where emotional intelligence would benefit people. But most people donโt practice that enough to know how to express it.