The 10 Most Overlooked Causes of Infertility-And How the Creighton Model Helps Identify Them

If you’ve been trying to conceive and keep hearing,

“Everything looks normal,”

or

“Just give it a little more time,”

I want you to know how incredibly common and incredibly frustrating that experience is. Many of the women and couples I work with have spent months or years feeling confused, unseen, or brushed off. They’re told their tests look fine. Their ultrasound is fine. Their hormones are fine. Yet… they’re not getting pregnant and ultimately they end up feeling totally dismissed.

That’s because most infertility isn’t “unexplained.”

It’s simply not being fully explored.

The issue is rarely a lack of effort or hope, it’s a lack of information.

Your cycle holds answers.

Your symptoms are telling a story.

Your body is giving clues. And not only clues sometimes really loud alarm bells.

They’ve simply been overlooked...

This is exactly why I love the Creighton Model FertilityCare System so much.

It doesn’t gloss over things.

It doesn’t make assumptions.

It doesn’t rely on averages or predicted “fertile days.”

Instead, it observes your actual cycle day by day and provides detailed insights that most medical evaluations miss altogether.

Below are 10 of the most commonly overlooked causes of infertility ones I see again and again and how Creighton helps uncover them with clarity and confidence.

1. Short Luteal Phase (Luteal Phase Defect)

If you’ve never heard of your luteal phase before, don’t worry most women haven’t.

But it is incredibly important. Your luteal phase can say a lot about your overall fertility.

Your luteal phase is the number of days between immediately after Peak Day and your next period. If it’s too short, even by a couple of days, implantation can’t happen effectively.

A short luteal phase can look like:

• spotting before your period

• cycles that feel “regular” but are actually hormonally weak

• periods that start earlier than expected

• PMS symptoms that feel intense or prolonged...make you feel like a total crazy person

What makes this easy to miss is that women often still bleed on predictable cycles.

Doctors may see a 28–30 day cycle and assume everything is perfect.

But with the Creighton Model, we measure the luteal phase with precision. We’re not guessing. We can see clearly if the post-peak phase is consistently too short. And once identified, there are several targeted ways NaProTechnology can support and strengthen the luteal phase.

2. Low Progesterone or Estrogen Levels

This one is enormous. And one I still to this day cannot believe how it is not talked about more.

Many providers test hormones on “Day 21” because that’s what the average textbook cycle recommends. But if you ovulate on Day 17… or Day 12...that test becomes meaningless.

Creighton changes the entire game by timing blood work exactly around your actual ovulation, not a predicted one.

Low progesterone can explain:

• early losses

• repeated spotting

• severe PMS

• anxiety

• fatigue

• difficulty sustaining early implantation

Low estrogen can explain:

• limited mucus

• short fertile windows

• weak ovulatory patterns

• cycle irregularities

When hormone levels are tested on the correct days, a much more accurate picture emerges and often, this alone is a major breakthrough for couples and gives you a greater picture of what is going on.

3. Poor Cervical Mucus Quality

Cervical mucus may not be the most glamorous topic, but it’s one of the most important for fertility and the main bio marker in the Creighton Model.

Healthy mucus:

• nourishes sperm

• protects them

• keeps them alive for days

• helps them reach the egg

Many women have no idea that mucus quality even matters or that it can be improved.

Signs of suboptimal mucus include:

• dryness

• tacky or sticky mucus

• cloudy mucus with no stretch

• a very brief fertile window

• no sensation of lubrication

Most fertility clinics don’t evaluate mucus at all. But with the Creighton Model, it’s recorded daily, which means we can quickly spot if your body isn’t producing the kind of fertile-quality mucus needed for conception.

And the best part: There are science-backed protocols that help improve mucus quality and many women can see improvements within a few cycles.

4. Silent (or Minimally Symptomatic) Endometriosis

Endometriosis is widely misunderstood.

So many women believe:

“If I had endometriosis, I would be doubled over in pain.”

Not true.

Some women have extremely subtle signs. Others have almost no pain but still have endometriosis severe enough to impact fertility.

Clues on a Creighton Model chart might include:

• tail-end brown bleeding

• pelvic pain that seems “mild but weird”

• mid-cycle pain that doesn’t match ovulation

• cyclical spotting

• unusual mucus patterns

• chronic inflammation signs

Creighton Model-trained physicians take these patterns seriously and will not dismiss symptoms just because they aren’t dramatic.

For many women, identifying endometriosis and receiving NaPro-trained excision surgery (not just ablation) becomes the turning point in finally achieving pregnancy.

5. Ovulation Dysfunction (Even With Regular Periods)

One of the biggest surprises for many couples is discovering that regular cycles don’t necessarily mean ovulation is happening.

You can bleed every month and still not actually ovulate.

This may look like:

• very long mucus cycles

• mucus patterns that start and stop

• cycles with no Peak Day

• cycles that vary dramatically month-to-month

Creighton charts make ovulation (or lack of it) visible.

There is no guessing.

No relying on apps.

No assuming.

And once we know what’s happening, we can address the root cause.

6. PCOS That Doesn’t Fit the Textbook

PCOS is one of the most misdiagnosed or completely missed conditions in women’s health. Which is crazy because PCOS "remedies" or "diets" are all over social media. Which leads me to believe, do people actually know how to treat it?

A woman might be told she doesn’t have PCOS because:

• her weight is “normal”

• her cycles are “pretty regular”

• her ultrasound looks fine

• her labs aren’t alarming

Yet her chart may tell an entirely different story.

A Creighton Model chart often reveals:

• long pre-ovulatory phases

• inconsistent mucus

• multiple patches of fertile signs with no ovulation

• long cycles

• cycles with no clear fertile pattern

These are early signs that something in your ovulation system isn’t functioning optimally — and early detection means earlier, more effective treatment. PCOS can be treated. It is not a “death sentence” for your fertility. Yet it remains deeply misunderstood. The truth about how to effectively manage PCOS needs to be everywhere, billboards, PSAs, social media, you name it. People need to know. Right now, what the world is teaching about PCOS, how to diagnose it, how to treat it is moving dangerously close to the wrong path. We need to change that.

7. Chronic Inflammation or Autoimmune Issues

Inflammation affects everything, hormone production, ovulation, mucus quality, implantation, uterine lining, early pregnancy.

And here’s the tricky part:

Most women with inflammation don’t feel “sick” or obviously inflamed.

The Creighton Model helps reveal inflammation by showing:

• repeated cycle irregularities

• early or late cycle spotting

• unexpected mucus patterns

• cycles that don’t follow expected physiological patterns

When we see these clues across multiple cycles, they often lead to deeper testing for inflammation markers, thyroid concerns, autoimmune issues, or low-grade pelvic inflammation.

8. Hidden Infections

Not all infections cause burning, itching, or discomfort. Some are incredibly quiet and mild but still significantly impact fertility.

A Creighton Model chart may show patterns of:

• abnormal discharge

• certain mucus changes

• persistent spotting

• unusual bleeding patterns

These signs help providers know when to run specific cultures or tests that would normally never be considered.

Again, this is where the root-cause approach shines.

9. Subclinical Thyroid Dysfunction

Thyroid problems often hide underneath “normal” lab results because the reference ranges are so wide.

But the thyroid is deeply connected to:

• ovulation

• cervical mucus

• progesterone production

• early pregnancy survival

A Creighton Model chart can reveal thyroid-related cycle patterns long before standard testing would ever catch it.

Things like:

• long cycles

• short luteal phases

• poor mucus quality

• repeated spotting

• very inconsistent ovulatory patterns

These clues help providers dig deeper and run a full thyroid panel, often uncovering imbalances that are extremely treatable.

10. Timing Intercourse on the Wrong Days (Through No Fault of Your Own)

I wish I could shout this from the rooftops:

Apps cannot tell you when you’re fertile!!!!!!!

They can guess, but they cannot actually identify ovulation.

If your cycle varies even slightly, which is totally normal and can literally happen from cycle to cycle, an app can easily miss your true fertile window.

The Creighton Model solves this by showing:

• exactly when your body begins producing fertile-quality mucus

• exactly when you reach Peak Day

• exactly how long your fertile window truly is

This alone has helped so many couples conceive simply by correcting the timing — without medications or interventions.

Why This Matters So Much

When you understand your cycle,

you understand your fertility.

You’re not waiting in the dark.

You’re not guessing.

You’re not relying on averages or one-size-fits-all testing.

You’re partnering with your body instead of working against it.

The Creighton Model gives women:

• clarity

• confidence in understanding exactly what is going on

• a sense of control

• and a roadmap for real solutions

• root cause answers

  
  

And NaProTechnology builds on all of this with targeted, respectful medical care that looks at the actual root cause.

Repeat after me:

I am not broken.

My body isn’t working against me .

I simply need an approach that listens and knows how to interpret what my cycle is telling me.

If you have felt stuck, dismissed, or confused on your fertility journey…

I want you to know this:

There are answers.

There is root cause testing.

There is a system designed to investigate these overlooked signs.

And you don’t have to walk that road alone.