There are weekswhen I ask ChatGPT how it's possible I can't stop crying and if I should be worried about it. And there are weeks when I listen to the dirtiest reggaeton on repeat, so confident that I see myself capable of posting a selfie in the bathroom mirror. But neither at one moment nor the other am I aware that this feeling is a product of my hormones. Every month I feel cheated by myself: once again, I surprise myself, as if this same process hadn't repeated itself for almost 20 years. That's why, and for when I feel like I can't trust myself, I've monitored what happens to my body and mind in the 28 days of my menstrual cycle, according to my mobile app.