Irregular menstrual periods are the norm for some women, and that's usually fine. But if you’re used to periods that arrive like clockwork and suddenly they don’t, figuring out the why of it can be challenging. There are the obvious life changes, like getting pregnant, breastfeeding, or entering perimenopause or menopause. In addition, pretty much any health issue, from endometriosis to thyroid disorders to stress, can cause big swings in your period patterns. Hormonal birth control, certain medications, being at an unhealthy weight, eating disorders, and excessive exercise or weight loss are also possible culprits. For context, a normal menstrual cycle ranges from 21 to 35 days, but 14-25% of women have cycles that are irregular. What does that mean? It could be that you’ve skipped three periods in a row—or over the course of a year—and you know you’re not pregnant. Or maybe your periods have become irregular suddenly...or they now last longer than 7 days...or your periods are super-heavy so you need more than one pad or tampon every hour or two...or you’ve got a fever or some vaginal discharge. These are all reasons to try to figure out what's up. With so many possible explanations for irregularity, it can be helpful to start tracking your periods on a calendar or an app to help you see patterns. Then, you can bring that info to your ob/gyn or other health care practitioner so they can help figure out what’s going on. Believe us, you’ll be a star patient if you arrive with this info, and your practitioner will be able to get an idea of the big picture. It’s hard to pull all this data from your brain, so we’re all for nerding out with tracking! Meanwhile, you can dial up the self-care by experimenting with herbs that help with PMS and might—might—have the added benefit of regulating menstruation, including black cohosh, cinnamon, chasteberry, and turmeric.