Do You Have Irregular Periods? Here’s How To Recognize Pregnancy Symptoms

If you have regular menstrual cycles, one of the first signs you may be expecting a baby is a missed period. Since people with 28-day menstrual cycles typically get their period about 14 days after ovulation, a period that doesn’t show up when expected could mean it’s time to take an at-home pregnancy test.

But what if your menstrual cycle isn’t regular? As many as 25% people of childbearing age have cycles that fall outside of the normal range, and that can make it pretty difficult to use the arrival of your period as a benchmark for possible pregnancy. Here’s what to know about recognizing pregnancy when you have irregular periods.

What Are Irregular Periods? 

Irregular periods are defined by several different characteristics, but typically relate to how often you get a period and the severity of your symptoms.

You might have irregular periods if you:

• Go less than 21 days or more than 35 days between cycles 
• Have a lot of variability between lengths of cycles
• Have periods that last longer than seven days
• Skip several periods at a time

Many with irregular periods may also experience:

• Heavy bleeding that soaks through a pad or tampon more than once per hour
• Extreme pain or cramping, especially if it affects your quality of life
• Feel dizzy, weak, or lightheaded during or after your period
• Pass blood clots larger than a quarter during your menstruation

Causes of Irregular Periods 

Maybe you’ve always had irregular periods, or maybe it’s a new thing—either way, there are various reasons why your period may be irregular. But keep in mind, it's not unusual to experience cycle changes from time to time. For example, sickness, stress, and travel can throw off your cycle temporarily. You might also have irregular periods for a while after giving birth or nursing, or even after stopping birth control.

“If you skip one period, first make sure you are not pregnant and then wait to see if you have a period next month," says Suzanne Bovone, MD, OB-GYN at Pediatrix Medical Group in San Jose, California.

If you skip two months, then you should make an appointment to talk with your health care provider, says Dr. Bovone. Similarly, if your periods suddenly become much heavier or last longer than usual, that’s also a sign that you should talk with your provider. You could have a new health condition, a uterine growth, or a hormonal imbalance. 

Other causes of irregular periods include:

• Polycystic ovarian syndrome. Those with polycystic ovarian syndrome (PCOS) don’t ovulate monthly, so they often go long periods of time between menstrual cycles as well. PCOS can also cause heavy bleeding when periods do occur.
• Weight changes. Gaining or losing a significant amount of weight can cause sudden changes to your menstrual cycle, Dr. Bovone says. Eating disorders can also disrupt normal menstruation.
• Stress. Chronic stress—like from a difficult job or family situation, for example—can cause irregularity. Significant acute stress, such as a loss, move, or devastating event, may also cause irregularity.
• Excessive exercise. Whether you’re an athlete that trains daily or someone who’s just taken up a more intense exercise regime than you’re used to, extreme amounts of exercise can cause your period to become irregular and may be a sign that you need to slow down.
• Certain medications. Dr. Bovone says some medications and over-the-counter (OTC) supplements can change your cycle or cause spotting. Common culprits include blood thinners, anti-anxiety medications, and anti-epileptic medications.
• Certain health conditions. Monte Swarup, MD, OB-GYN in Chandler, Arizona and founder of HPV Hub, says thyroid and pituitary gland disorders can cause irregular periods, as can bleeding disorders (like hemophilia and von Willebrand disease).
• Uterine abnormalities. Polyps and fibroids are two different types of benign growths that can occur in the uterus. They can both cause abnormal bleeding patterns and interfere with ovulation.

Why Irregular Periods Can Impact Getting Pregnant 

Whether you’re hoping to become pregnant or not, it’s important to find out why your periods are irregular. Abnormal menstrual cycles usually point to a larger issue unless you’re nursing or going through menopause, so if you’ve noticed an irregular pattern, you should make an appointment with your health care provider.

If you are trying to get pregnant, it’s even more important to see a provider about your irregular periods because you may or may not be ovulating. Ovulation is a critical step in the process (it’s when your ovary releases an egg to be fertilized), so if you’re not ovulating at all, you won’t be able to get pregnant. Your health care provider can help you determine if you are having ovulatory or anovulatory cycles and make recommendations with that information.

Even if you’re ovulating, explains Dr. Bovone, irregular cycles can make it hard to figure out exactly when you are. Getting the timing right, aka pinpointing your fertile window, is also important to successfully getting pregnant.

Signs of Pregnancy With Irregular Periods

Though you can’t depend as reliably on a missed period as a sign of pregnancy, there are other signs you can look for if you’re waiting to take an at-home pregnancy test.

• Feeling sick (Robert Atlas, MD, OB-GYN and chair of the department of obstetrics and gynecology at Mercy Medical Center in Baltimore, says about 70% of people will have nausea and occasional vomiting at the start of pregnancy.)
• Excessive tiredness
• Breast changes like swelling and tenderness (But Dr. Atlas cautions that can also happen just before you get your period, so consider breast changes along with other signs and symptoms.)
• Light spotting
• Headaches
• Sudden cravings for or aversions to food
• Mood swings
• More frequent urge to pee
  

What To Do About Irregular Periods if You Want To Get Pregnant

Some of your approach to getting pregnant with irregular periods will depend on why they’re irregular. If you’re ovulating but have longer than average cycles, your strategy may be different than someone who isn’t ovulating at all.

In general, though, there are some best practices to getting pregnant with irregular periods. Dr. Swarup says it’s important to eat nutritious foods and get plenty of exercise. If you're having sex to get pregnant, you'll also want to have regular intercouse in order to improve your chances.

You may also want to consider using some technological tools to keep tabs on your cycle and make it easier to figure out when you’re ovulating. Since you’re the most fertile right before you ovulate, says Dr. Bovone, it helps if you’re tracking your entire menstrual cycle from beginning to end.

She suggests using a period tracking app to better understand your cycle length. For those with regular, 28-day periods, ovulation would normally happen between days 10 and 15 of the menstrual cycle, but if your periods are irregular, you can’t rely on that. An app, such as the FDA-cleared Natural Cycles, can show you a clear picture of what your cycle length looks like overall.  

Dr. Bovone also recommends adding OTC ovulation detection kits to your monthly cycle. These provide a way to double-check your period tracking. “Once you get a period, you can count back 14 days and see if your ovulation testing is matching what the calendar predicted,” she explains. They also can help you time your sex for conception if you use them regularly throughout your cycle. They may also inform you if you’re having anovulatory cycles.

The bottom line, though, is that if you have irregular periods and want to get pregnant, it’s a good idea to receive a full workup from your health care provider rather than trying to navigate conception all on your own.

“A thorough history, physical, lab testing, and ultrasound will be done to determine a reason [for your irregular periods],” says Dr. Bovone. “Sometimes a reason is not found, but fortunately, infertility doctors are able to assist patients in achieving their pregnancy goals.”