If you’re reading this, you’ve likely had your period for awhile. And I bet you probably think you’ve got a pretty good handle on all things period related: tracking your cycle, period products, cramps, PMS and so on…

After all, you have been reading my stuff right? 😉

Before—or when—you got your very first period (I bet you remember it well!), it would have been great if your mom, a sex ed teacher or another woman in your life gave you a primer. Ya know, things like….

It’s more likely however, that you didn’t learn much of anything. And now as an adult woman, there is SO MUCH you’re wanting to know because you didn’t get the basics when you were younger.

Yes, I think we all need a grown up version of “the talk”. More on that in another post.

As more research is being done, we’re learning more than we ever thought possible about how our health can affect our periods and vice versa, and what’s really going on at that “time of the month”.

As you can imagine, I’ve come across some pretty wacky things in my work over the years, so I decided it was high time I created a list of the strangest, most surprising and shocking period-related truths.

10 interesting facts you didn’t know about your period:

#1. Other Parts Of Your Body Can Bleed During Menstruation

Say what?! As if menstrual bleeding weren’t enough, some women have conditions which cause bleeding in other parts of their bodies at the same time as their periods.

Women with endometriosis—a painful condition that causes the tissue that lines the inside of the uterus to grow outside the uterus—can also experience nosebleeds which are triggered by the same period hormones. This happens because endometriosis can grow in other areas including the lungs and nasal cavity.

Another condition called “vicarious menstruation” can even cause women to bleed from their eyes, according to a case report published in the journal Ophthalmic Plastic & Reconstructive Surgery. I know, it sounds super-scary but take heed. “Bloody tears” as it’s known is extremely rare so no need to worry!

#2. Your Period Can Make You Sick

Here’s a scenario you probably know well: you’re getting your period and suddenly you come down with a cold, sinus infection or some other illness. I hear about this constantly from women. They always ask “Is this all in my head or is my period actually making me sick?”

It’s been hypothesized that around ovulation time and into the second half of your cycle, your immune system function becomes suppressed so that your body doesn’t reject sperm. And then if you do become pregnant, your body also doesn’t reject the embryo.

CRP, a biomarker for inflammation happens to be higher in the second half of the menstrual cycle, and it appears to positively correlate with PMS symptoms like mood issues, bloating, cramping and breast pain.

So basically, your immune function is lower and you’re more inflamed in the lead up to your period.

Likewise, if you have asthma, you might notice that your symptoms worsen during that time of the month.⁠ Your body is also more sensitive to allergens, and your lung capacity actually shrinks during your period.⁠ (I know, #crazy.)⁠ This “perimenstrual asthma” or premenstrual asthma (PMA) affects between 19 and 40 percent of women with asthma.

#3. Getting a Period Doesn’t Mean You’re Ovulating

If you’re trying to get pregnant, getting regular periods doesn’t necessarily mean you’re ovulating or fertile. In fact, according to this study, 37 percent of women between ages 20 and 49 had “silent anovulation,” meaning they had a period but didn’t ovulate. Whoa!

The best way to figure out if you are ovulating is to start tracking your basal body temperature and your cervical fluid patterns. Your basal temperature is your temperature upon awakening, and your cervical fluid changes according to hormone fluctuations each week of your cycle. I explain exactly how to chart your cycle in this post. It’s a lot easier than you might think!

You can also get your progesterone levels tested to determine if you’re ovulating.  Lets Get Checked is my go-to for at home hormone test kits and you can grab there Progesterone Test here.  Be sure to use discount code Hormones20 to get 20% off the price of the test.

#4. You Tend To Spend More Money On Your Period

We’ve all used a little retail therapy to distract ourselves from period-related aches and fatigue, but it turns out there might actually be some science behind the urge to shop.

In fact, according to a January 2011 study, women on their periods had less control, were more likely to make impulse buys and have buyer’s remorse. Thankfully, during this time of your cycle you’re likely to fill your shopping cart with little items like a bouquet of flowers, a lipstick or a magazine. My suggestion is don’t shop at Sephora or anywhere that has an endless array of small items near the checkout!

Unfortunately for your bank account, once your period is over and ovulation approaches, the spending doesn’t stop. Rising estrogen boosts your mood, and also makes you more optimistic about how much money you have to spend–a combination that makes you enjoy treating yourself even more.

So although hitting the flash sale sites during the first half of your cycle might be immediate gratification, the endorphin rush won’t last when you see next month’s credit card bill! Make sure to be cognizant of this fact the next time you have your period.

#5. Light Exposure During Sleep Can Affect Your Menstrual Cycle

Srsly, I am serious! Yup, if you have irregular periods or no period, sleeping with  your curtains open during a full moon may actually help. Or if you don’t see the moon where you live (like me in NYC), then sleeping with a nightlight or a dim hallway/bathroom light on works too.

That’s because both natural sunlight, moonlight and indoor lighting affect melatonin, “the sleep hormone”, which controls the release of the hormones that tell your body when your period should start and end. Yes, your circadian rhythm is intricately connected to your menstrual cycle, so sleep is uber important!

This practice is known as lunaception, and the idea is to help align your own cycle with the moon cycle. It involves sleeping in complete darkness for the entire month, and then using a nightlight or allowing natural moonlight into the room on the evening before the full moon, the day of the full moon and the day after the full moon. This might sound a little crazy, but I’ve actually found this to be effective with many of my clients who were trying to get back a period, regulate their cycle, or sync it with the moon cycle.

#6 On The Pill? Your Period Is An Imposter

I’m not a proponent for any form of hormonal birth control because of all the undesirable side effects, which I’ve written about here, here and here. At the very least, I want women to be 100% informed about the potential side effects of these powerful medications before venturing down this path.

The #1 reason women tell me they go on birth control is to regulate their periods. The thing is, if you are on a form of birth control and you still bleed every month, or a few times a year, that “period” is actually fake.

The reason? Birth control STOPS ovulation which leaves you in a state of hormone depletion. So during the placebo/sugar pill week, what you actually experience is “withdrawal bleeding.” Although the uterine lining doesn’t build up as much as it would if you were ovulating, the drop in hormones (because you’re taking sugar pills and not pills with synthetic hormones in them) causes the thin lining that is there to weaken and shed. Bottom line: If you’re not ovulating, you’re not having a real period.

#7. Your Period Doesn’t Sync With Your BFF

You’ve probably heard that women who live or work together tend to have the same cycles, but that seems to be an old wives’ tale. This one hurts me as much as it hurts you, I promise.

According to a recent survey conducted by Clue, one of my fave period and ovulation tracking apps, only 79 of the 350 pairs of women studied had cycles that, over a 3-month period, started to sync up.

NOTE: I am still not sure about this one! I’m all for the science, but there are some mysteries science can’t explain. The many women I’ve synced my cycle with over the years is just uncanny – so while I don’t doubt the results of this study, I do think there’s more to the story!

#8. Stress Can Cause Spotting

Between work and finances, juggling family, friends and all that you have to do every day, I know you’re maxed out. Last week I read this survey that showed not only are women stressed, but 50 percent say stress and anxiety affect their personal wellness.

Yup, half of us are admitting that ongoing psychological stress is wreaking havoc on our physical & emotional health. Bah, I know I’m always the bearer of bad news.

If you have spotting, it is most often due to low progesterone. But how does low progesterone happen? Remember, all of your hormones are constantly talking to each other, so when one hormone is affected, the others are too.

When stress levels are high – especially during the holidays and in the aftermath of the holidays – your sex hormones can take a serious hit. As cortisol and epinephrine kick into high gear, your pregnenolone and progesterone subsequently become depleted, which in turn can lead to spotting in between periods.

If you want to get your stress levels checked, I recommend this Cortisol Test from Lets Get Checked.  Be sure to use discount code Hormones20 to get 20% off the price of the test.

#9. Your Period Can Affect Your Digestion

If you find yourself running to the bathroom when you have your period, you’re not alone. According to this study, 73 percent of the women surveyed experienced abdominal pain and diarrhea before and during their periods. I even wrote a post about periods and poops, because it’s such “a thing”.

Before your period starts, progesterone levels dramatically drop which causes your uterine lining to shed. During this process, prostaglandins – hormone-like lipids – stimulate muscle contractions in your uterus. Yet if too many prostaglandins are released, it can affect the bowels and lead to diarrhea.

The good news is that you don’t have to suffer every month. An effective way to combat period-induced bowel troubles is to get your omega 3/omega 6 ratio in balance, which will lower inflammation and the subsequent production of pro-inflammatory prostaglandins. I show you how to do that in this post.

#10. Your Period Can Increase Your Sex Drive

Ah, period sex. Quite possibly the most controversial topic in our culture, second only to periods of course! Sex might be the LAST thing on your mind when you’re irritable, tired and dealing with cramps—not to mention it can be messy—but if you are in the mood, you’re not some freak of nature.

In fact, research has found that many women find period sex to be the only thing that gives them any relief from their cramps and headaches.

Since levels of progesterone—the hormone that tends to suppress libido—are low after you start your period, and estrogen – one of the hormones that revs your sex drive – begins it’s ascent, your desire for sex may increase. Additionally, there may be a small uptick in testosterone (our libido stoker) during your period.

Additionally, according to my friend Isa Herrera MSPT,CSCS, a badass women’s health physical therapist and founder of PelvicPainRelief.com, lots of women know that this time of the month means their chances of getting pregnant are virtually impossible (not entirely though!), and they feel more open to sex.

She goes on to say that since the cervix is lower during menstruation, it can stimulate the g-spot which is on the front wall of the pelvic floor muscles. So it makes sense when the uterus is heavy and the cervix is low, that there is an increase in arousal via g-spot stimulation.