I got my period on Saturday, February 9th. The same day the new moon started. The same day I spent three hours digging four cars out of my driveway that were buried under 26 inches of snow. With my partner—who also just started her period. The same day a friend desperately texted me that her and her girlfriend were snowed into their house—bleeding. Together.

The more ladies I talked to about the bleedin’ blizzard, the more blizzard bleeders came out of the snow banks. What cosmic forces were at work that weekend? Is the “ladies who live/love together, bleed together” theory real, mythological or just an icy joke from Mama Nature? Was she PMSing, too?

Published scientific papers on the topic find no concrete evidence that menstrual cycles sync like a pile of iProducts, and those that do are usually geek-bashed for statistical faultiness. Most famously, Martha McClintock studied 135 women living in a college dorm together in 1971. For an entire school year, these women recorded their period start dates. McClintock found that close friend groups started bleeding significantly closer together at the end of the school year than they did at the beginning. “The McClintock Effect” spread like a drop of blood in a toilet bowl and the rumor’s been rolling, but never proven, ever since.

Some say that women evolutionarily synced so that giant-chicken-leg-eating idiot cavemen, ragingly horny from the smell of ovulating pheromones, wouldn’t get confused about which women were actually ripe for impregnation. Other boring period theorists site pure coincidence and some math blather about menstrual variation.

Then there’s the Bleeding Blizzard Sync-Up. During the new moon! The lunar cycle from new moon to full moon takes an average of 29.5 days. Oh, hey – so does the menstrual cycle. Woo-womb womyn have been claiming forever that the cosmic pull of the moon dictates women’s periods, but apparently there’s an emerging trend in intentionally lining up your uterine lining-shedding with the lunar lifecycle called “lunaception.”

Lunaception is the practice of balancing your menstrual hormones by manipulating the light in the room that you sleep to mimic the moon’s cycle. Supposedly, most of our hormone production happens at night, and before electricity, women’s resting bodies would take hormonal cues from the moon’s light, with the bright full moon signaling the body to ovulate and the dark new moon triggering menstruation. However, with today’s glowing computer chargers and flashing cell phones, the sleeping female body has been knocked off its moonlit menstrual path.

Donielle Baker, the lunaceptionista behind NaturallyKnockedUp.com, says that syncing with the moon is one the healthiest ways to menstruate, improve fertility and heal the body from hormonal traumas such as miscarriage. Here’s what you have to do:

Start sleeping in complete darkness. “Cover up alarm clocks and windows that allow in any artificial light,” says Baker. “If you often get up at night to use the restroom, place dim nightlights in the hallway and bathroom and refrain from turning on overhead lights.”

The day before the full moon, allow a small amount of light into your room: “Natural moonlight through a window is best. Otherwise, use a very white, dim nightlight.” Use the nightlight for three nights, then go back to complete darkness until the next full moon. This will get you bleeding on the new moon and ovulating on the full moon. If your goal is pregnancy, knock the Birkenstocks during the three nightlight nights (though lunaception could be a great way to get knocked up, it’s probably not the best way not to get knocked up; don’t toss the condoms out in the snow yet). If you’ve got a regular period that’s off the moon cycle, grab a calendar, marking the first day of your period as day one. On day 14, start the three nightlight nights and then go blackout again. This’ll sync you up real good.

The Bleeding Blizzard Sync-Up taught me much about forces of nature, but most crucially, it taught synced ladies everywhere the importance of lavender heating pads, tampon backstock and how to put a plate of fresh-baked cookies down in front of your snow-shoveling, bleeding babe and back away—slowly, slowly back away.•