Irregular Periods: When to Take a Pregnancy Test, How to Track Ovulation, and Potential Causes

When you’re eager to conceive, you may become a master of reproductive cycles, early pregnancy symptoms, a good AMH level, and other fertility facts to help you get pregnant. But the question of when to test for pregnancy if irregular periods are your normal can still be a head-scratcher.

Irregular periods are fairly common, affecting up to ¼ of women and people assigned female at birth. While they can be personally frustrating—especially if they’re accompanied by severe menstrual symptoms—they can also make it harder to gauge your fertile window and when to take a test.

You’ll get the most reliable test results if you play the long game: Try taking your test 2 weeks after you think you may have conceived. Additionally, with a more thorough understanding of how reproductive rhythms work, you may help optimize your chances of pregnancy with an irregular cycle.

3 Pregnancy Testing Guidelines for People with Irregular Menstrual Cycles

If you have irregular periods and need to take a pregnancy test, there are several golden rules to keep in mind:

1. Monitor your symptoms – Many people notice the early signs of pregnancy even before a test confirms one. Some of the most common symptoms of early pregnancy include fatigue, breast tenderness and enlargement, and nausea. If you notice several of these symptoms, it may be a sign to take a test.
2. Test 2 to 3 weeks after attempted conception – If you attempted to get pregnant during your (best guess!) fertile window, try to wait 2 to 3 weeks afterward to test. Though implantation can occur less than a week after your attempt, your body won’t release pregnancy hormones until after 11 days or so.
3. Test in the morning – Your urine is the least diluted in the morning. This makes it easier for pregnancy tests to pick up on hCG (the hormone found in your urine and blood when you’re pregnant).

In and of themselves, at-home pregnancy tests can be highly accurate—especially if you take a test twice.

That said, consulting with a healthcare provider may help you determine the best time to test, as well as when to try for a baby. Healthcare providers can also administer blood pregnancy tests, which may be able to screen for pregnancy earlier than their at-home counterparts.

How to Track Ovulation with Irregular Periods

Generally speaking, consistent cycle lengths make it easier to track ovulation. Most people ovulate around 2 weeks after the onset of menstruation, making those 6-or-so days beforehand the fertile window.

When your cycle lengths are irregular, though, (including irregular ovulation) fertile windows can be harder to pinpoint. Fortunately, your body may give you some physical signals of when you’re most fertile. The good news? Learning to read these cues can make it easier to anticipate when you’ll ovulate:

• Your basal body temperature – Basal body temperature, or BBT, is your body’s lowest temperature when at rest. In fact, it’s only achieved during sleep. When a person ovulates, their BBT “jumps” by between .5º and 1ºF.

For this reason, tracking BBT is known as a fertility awareness method (FAM). To track your ovulation window accurately, you’ll need to take your temperature (with a basal body thermometer) every day as soon as you wake up in the morning.

• Your cervical mucus – You may have noticed it before, but your cervical mucus (or “discharge”) changes in texture throughout your menstrual cycle. Near ovulation, it becomes slippery and elastic to help trap and lure any sperm traveling toward your egg.
• Your cervix position – Another lesser-used method is testing your cervical position. When you’re most fertile, the cervix retreats higher into your body and becomes more pliable to the touch. If you’re up for it, you can feel for your cervix to see whether you’re in your fertile window.

Ovulation predictor kits can also make it easier to gauge your fertile window. These kits screen your urine for LH, or luteinizing hormone, which increases 1 to 2 days before you ovulate.

Is it harder to get pregnant with irregular periods?

Irregular menstrual cycle lengths can make it difficult to pin down your fertile window—those days leading up to ovulation when you’re most likely to conceive. This is because your cycle lengths may be linked to highly variable ovulation cycles.

It’s also important to note that “irregular periods” can refer to varying cycle lengths as well as severe and even debilitating premenstrual and menstrual symptoms. These could include:

• Severe cramping or pain preceding or during menstruation
• Nausea
• Vomiting
• Very long bleeding periods
• Extremely heavy menstrual flows

Struggling with debilitating menstrual symptoms could be a sign of an underlying health condition, which may impact your fertility. Some common reproductive conditions and possible causes linked to menstrual irregularity include:

• Endometriosis
• Pelvic inflammatory disease (PID)
• PCOS (polycystic ovary syndrome)

Knowing this, it’s important to seek assessment from a healthcare provider if severe symptoms accompany your irregular cycle lengths. Though reproductive health conditions can have fertility implications for hopeful parents, many are treatable or manageable with proper care. Reach out to a doctor about fertility treatment options if you are concerned about your reproductive health.

What causes irregular menstrual and ovulation cycles?

Because menstrual irregularity is so common, it’s not always counted as a health concern. However, if your inconsistent cycles are causing you distress and you’re struggling to get pregnant, it may be important to work with a healthcare provider to identify a root cause.

Understanding what possible causes could be behind your symptoms can help put your mind at ease as you plan your pathway to parenthood.

Weight and Weight Fluctuations

Weight plays a dominant role in hormonal balance, in part because many sex hormones are stored in fat (also called adipose tissue). If your weight changes frequently, you may notice major swings in when and whether you ovulate, and when you get your period.

Additionally, being over- or underweight can result in irregular menstrual cycles.

Hormonal Imbalances

A delicate feedback system of hormones governs your ovulation and menstrual cycles, and when it gets thrown out of whack, it can disturb your regular cycles. Hormonal imbalances can be mild, or they can be rooted in an underlying hormonal condition.

Some common hormone-related conditions that contribute to irregular periods include:

• Polycystic ovary syndrome (PCOS) – PCOS impacts an estimated 5 to 10% of reproductive-aged American women and people assigned female at birth. It’s characterized by an excess of androgens (a male sex hormone). One of the most common symptoms is irregular menses; other symptoms include abnormal hair growth, acne, and weight gain.
• Thyroid conditions – Since thyroid disorders like hyperthyroidism and hypothyroidism interfere with the endocrine system, they can also disrupt your period patterns. Some of the most common menstrual symptoms linked to thyroid disorders are abnormally heavy or light period flow, amenorrhea, and abnormally long periods. Fortunately, thyroid conditions can often be corrected with thyroid medication.

Stress Levels

States of stress are largely triggered and maintained by hormones, so if your stress levels are frequently in flux, you may observe irregular menstrual cycles. Cortisol, a key stress hormone, helps your body prepare to respond to threats. When your body disburses it, maintaining “fight or flight” takes precedence over other hormonal activities, including your fertility cycles.

If you’re concerned that your stress levels are interfering with your fertility, your best course of action is to consult with a healthcare provider. They can help assess and advise you on which lifestyle or psychiatric changes may help you lead a lower-stress life.

Postpartum Hormones

If you’re trying to get pregnant again after having a baby, you’ll naturally experience some menstrual irregularity due to hormonal changes.

Breastfeeding parents, in particular, typically take several weeks to re-regulate their cycles (most commonly between 6 and 12), since prolactin, a breastfeeding hormone, suspends routine ovulation cycles. Supplementing breast milk with formula may help restore your usual menstrual cycles faster.

Lifestyle Factors

Many of the rhythms and traits of your menstrual cycles are susceptible to lifestyle. Factors that can interfere with your reproductive rhythms include:

• Your sleep – How much you sleep, when you sleep, and the quality of your sleep can all play a role.
• Your medication use – Some psychoactive drugs, oral contraceptives, steroids, and other medications can contribute to irregular cycles.
• Substance use – Recreational use of alcohol, nicotine, and other drugs can impact fertility cycles.

Nutrition can also play a key role. If you don’t meet your nutritional needs over a sustained period, your body will detect it can’t keep both you and a growing baby healthy. As such, you may notice irregular periods or amenorrhea (missed periods). If you want to explore other options like fertility herbs for pregnancy or vitamins to get pregnant fast, talk with your doctor about what is best for you.

Testing with the SneakPeek® Test

Once the pregnancy test reads Yes!, you can keep taking a conscious approach to your parenthood journey with the SneakPeek Early Gender DNA Test®.

With this at-home test, you can learn your baby’s predicted fetal sex as early as 6 weeks into your pregnancy with over 99% clinically proven accuracy. It’s why SneakPeek is the #1 OBGYN-recommended at-home early fetal sex test trusted by over 1 million parents.

Get to know your future baby earlier by picking up your test today.

Editorial Policy

At SneakPeek, our commitment is to provide accurate, up-to-date, and reliable information to empower our readers. Our content is thoroughly researched, reviewed by medical experts, and fact-checked to ensure its credibility. We prioritize the well-being and education of our readers, and our editorial policy adheres to the highest standards of integrity and accuracy in all our articles.

This post has been reviewed for accuracy by:

Sarah Cacia

Sarah Cacia, currently leading as the Director of Business Development at Gateway Genomics, parent company of SneakPeek, brings an impressive blend of bioengineering expertise and clinical business acumen. Her extensive experience, marked by roles at renowned institutions like Genentech and UC San Diego's Cardiac Mechanics Research Group, underpins her deep understanding of biotechnology and clinical research. A UC San Diego alumna with a Bachelor of Science in Bioengineering: BioSystems, Sarah's rich professional background empowers her to provide authoritative insights into the cutting-edge developments in the field.

Sources:

1. National Institutes of Health. What are menstrual irregularities? https://www.nichd.nih.gov/health/topics/menstruation/conditioninfo/irregularities
2. Healthline. 15 Early Signs and Symptoms of Pregnancy.
3. https://www.healthline.com/health/pregnancy/early-symptoms-timeline
4. Cleveland Clinic. How Soon Can You Tell You’re Pregnant? https://health.clevelandclinic.org/how-early-can-you-tell-if-you-are-pregnant
5. Cleveland Clinic. Home pregnancy tests: Can you trust the results? https://www.mayoclinic.org/healthy-lifestyle/getting-pregnant/in-depth/home-pregnancy-tests/art-20047940
6. Healthline. What Is Ovulation? What to Know About Your Menstrual Cycle.
7. https://www.healthline.com/health/womens-health/what-is-ovulation#timing
8. The American College of Obstetricians and Gynecologists. Fertility Awareness-Based Methods of Family Planning. https://www.acog.org/womens-health/faqs/fertility-awareness-based-methods-of-family-planning
9. Verywell Family. What Does a Fertile Cervix Look and Feel Like? https://www.verywellfamily.com/what-does-a-fertile-cervix-look-and-feel-like-1960297
10. Parents. How to Use Ovulation Test Strips. https://www.parents.com/using-ovulation-test-strips-to-predict-fertility-7551221
11. Cleveland Clinic. Irregular Periods. https://my.clevelandclinic.org/health/diseases/14633-abnormal-menstruation-periods#symptoms-and-causes
12. National Library of Medicine. Obesity, estrogens and adipose tissue dysfunction – implications for pulmonary arterial hypertension. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7506791/
13. Verywell Health. How Weight Gain and Weight Loss Affect Your Period. https://www.verywellhealth.com/changes-in-your-weight-and-missing-your-period-4105209
14. Office on Women’s Health. Polycystic ovary syndrome. https://www.womenshealth.gov/a-z-topics/polycystic-ovary-syndrome
15. National Library of Medicine. The Menstrual Disturbances in Endocrine Disorders: A Narrative Review. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7887462/
16. Johns Hopkins Medicine. Thyroid Disorders in Women. https://www.hopkinsmedicine.org/health/conditions-and-diseases/thyroid-disorders-in-women
17. Healthline. Can Stress Mess Up Your Period? https://www.healthline.com/health/stress/can-stress-mess-up-your-period#stress-and-the-menstrual-cycle
18. What to Expect. How Soon After Giving Birth Can You Get Pregnant? https://www.whattoexpect.com/pregnancy/pregnancy-health/how-soon-can-you-get-pregnant-after-giving-birth/
19. Mount Sinai. Is It Normal to Have Irregular Periods? https://health.mountsinai.org/blog/is-it-normal-to-have-irregular-periods/