It's one to two weeks before you start your period. The physical and emotional symptoms, like bloating, breast tenderness and crying are driving you mad.
Welcome to the premenstrual syndrome (PMS) club, where you’re in good company with 3 out of 4 menstruating women who experience a wide range of changes around that time of the month. No, PMS doesn’t stand for Please Make (it) Stop, even though you wish it would. But rest assured, it does stop about four days after your flow begins, as hormone levels start rising again.
PMS doesn't affect everyone, and the intensity of symptoms can vary from person to person. But research shows that PMS gets worse with age and/or stress.
While the exact cause of PMS isn't excatly clear, people who are senstive to fluctuating levels of hormones and change in serotonin levels are more likely to experience PMS. There's no medical test for PMS, instead it's more "experiential." That is, if you notice physical symptoms and mood changes before your period and these disappear once you're a few days into it, you probably have PMS.