Your Period Changed by 3 Days and Your Doctor Said 'It's Fine' - Is It?
Let me guess. You walked into your doctor's office with your period tracking app pulled up, ready to talk about how your usually reliable 28-day cycle has shifted to 25 days. You've been paying attention. You know something's different.
And what did you hear? "That's still within normal range" or "you're still getting your period, so it can't be perimenopause."
I’m sorry what?
Your Menstrual Cycle Is Actually a Vital Sign
Here's what should have happened in that appointment: your doctor should have recognized that your menstrual cycle is considered the fifth vital sign. We carefully track heart rate, blood pressure, and temperature, but somehow a shift in your monthly cycle gets brushed off?
When your cycle shortens, even by just a few days, and you’re “that age,” it's often the first sign that progesterone is starting to decline. This typically happens in early perimenopause, and yes, a 3-day change absolutely matters.
What's Really Happening When Your Cycle Shortens
Let me walk you through the science. In an textbook cycle, you ovulate around day 14(ish), and then the structure left behind (the corpus luteum) produces progesterone for about 14 days(ish). This second half of your cycle after ovulation is called the luteal phase.
<Please note: most women are NOT textbook. This is for explanation purposes.>
As we move through our late 30s and into our 40s, that corpus luteum doesn't work as efficiently as it used to. Instead of producing progesterone for 14 days, maybe it only does it for 9 or 10 days. That's how a 28-day cycle becomes a 25-day cycle.
This isn't just a scheduling inconvenience. It's your body signaling that hormonal changes are beginning.
Why This Actually Matters
When your luteal phase shortens, you're getting less progesterone each month. And progesterone isn't just about periods—you have progesterone receptors throughout your body, including in your brain, bones, and heart.
Less progesterone exposure often shows up as:
Sleep problems (especially waking up between 1-4 AM)
Mood changes (rage, anxiety, irritation, impatience, overwhelm)
Worsening PMS symptoms - even PMDD?
Heavier periods and maybe more bleeding days
Sound familiar? That's because perimenopause symptoms don't wait for your periods to completely stop. They begin when your hormones start fluctuating—and that can happen with even small cycle changes.
The Problem with "You're Still Cycling"
Let's clear this up once and for all: you can absolutely be perimenopausal while still getting regular periods. I’m a prime example!
Perimenopause is the transitional phase that can last 6-10 years. During most of this time, you're supposed to still be cycling. The official definition of perimenopause is actually based on cycle changes—and that includes these seemingly small shifts.
The medical research guidelines say early perimenopause begins when cycle length changes by 7 days or more. But in my clinical experience, women often start noticing symptoms when their cycles shift by just a few days. As I said, your body doesn't follow textbook timelines.
What You Can Do About This
First and most importantly: trust yourself. If you're tracking your cycle and notice changes, that information is valuable. Don't let anyone dismiss your observations.
Here's your action plan:
Document everything: Track your cycle length, flow changes, and symptoms throughout the month. This data becomes incredibly useful when advocating for yourself with healthcare providers.
Explore progesterone support: If you're experiencing sleep issues, mood changes, or worsening PMS alongside cycle changes, consider talking to a practitioner who understands hormones about progesterone support during your luteal phase.
Ask for comprehensive testing: Standard hormone panels often miss what's happening in early perimenopause. You might benefit from more detailed hormone testing that looks at the bigger picture. Progesterone testing should be done AFTER ovulation, if you do ovulate, unless you’re doing a month long test (there are great at-home options). In the at-home tests, you’re testing pretty much daily. It’s also possible it’s due to something else like a thyroid problem or high prolactin levels! This is why I like testing.
Find the right provider: If your current doctor dismisses your concerns, it may be time to seek out someone specifically trained in perimenopause and menopause care, like integrative medicine practitioners, or menopause specialists.
The Bottom Line
A 3-day cycle change might seem minor, but it's often an early indicator of the hormonal shifts that lie ahead. You're not imagining things, you're not being dramatic(ish), and it's definitely not "fine" if you're experiencing symptoms that affect your quality of life.
Understanding what's happening in your body empowers you to make informed decisions about your health. Your perimenopause journey is uniquely yours, and it often begins with subtle signals like a slightly shorter cycle.
You have the power to advocate for yourself, trust your body's messages, and seek the care you deserve. Don't settle for being dismissed when you know something has changed.