Understanding the Menstrual Cycle and Tracking Ovulation

Understanding the 4 Phases of the Menstrual Cycle

If you are trying to conceive, it is crucial to have a thorough understanding of your menstrual cycle. Without this knowledge, you may miss out on identifying the most fertile days, which can significantly reduce your chances of getting pregnant.

Tracking your menstrual cycle helps identify any potential issues or irregularities impacting your fertility.

The menstrual cycle is a natural, recurring process the female body undergoes to prepare for a potential pregnancy. It typically spans about 28 days, although variations are common.

The cycle involves four phases: menstruation, follicular, ovulation, and the luteal phase. Each is marked by hormonal changes to create an ideal environment for pregnancy.

Consult a doctor if you have any concerns.

Trying to Conceive?

Find an OB-GYN

The Four Phases of the Menstrual Cycle

Menstruation: Days 1-5

Your menstrual cycle begins on the first day of your period. This phase typically lasts around 3 to 7 days.

This is when your body uses hormones to signal to your womb that pregnancy has not occurred. Then, the lining of the uterus sheds. This is when your period begins.

While you're menstruating, keep track of the start date for accurate cycle monitoring.

During menstruation, many women experience pain or cramping in the lower belly, fatigue, bloating, acne, tender breasts, digestive issues, or other symptoms.

Many women also feel stronger emotions during this phase.

If you experience severe or debilitating effects, talk to your primary care doctor, OB-GYN, or gynecologist for ways you can get relief during your period.

Follicular Phase: Days 6-14

Following menstruation, the body enters the follicular phase.

Women are born with about 1-2 million eggs. As you age, your body loses eggs. By puberty, most women have 300,00 to 400,000 eggs remaining.

During the follicular phase of the menstrual cycle, your body sends hormonal signals to the ovarian follicles to prepare to release a developing egg.

The ovarian follicles are small sacs of fluid on the ovaries that contain an undeveloped egg.

When the body signals for this follicular phase, the ovarian follicles start working to mature the egg.

When an egg reaches maturity, it is released from the follicle to prepare for fertilization. In a normal cycle, only one egg is released at a time.

During this phase of your cycle, you will likely feel more energetic, happy, and inspired. This is due to a rise in the hormone estrogen.

Ovulation Phase: Day 14

When the mature egg is released from the ovary, it starts moving through the fallopian tube toward your uterus. This is the ovulation phase, which takes place usually on day 14.

Ovulation is a crucial time for conception, as the egg is viable for fertilization for about 12-24 hours.

To maximize your chances of getting pregnant, consider tracking ovulation through methods such as ovulation predictor kids or tracking changes in your basal body temperature.

If you are trying to prevent pregnancy, you should avoid unprotected sex in the days leading up to, the day of, and the day after ovulation.

Your basal body temperature is your temperature when you’re fully at rest.

If you’re tracking your cycle by taking your basal body temperature, you should take your temperature every morning as soon as you wake up, before getting out of bed.

You may see a slight dip in temperature right before ovulation, and a sharp increase when you ovulate. This is due to the hormone changes that happen during ovulation.

During ovulation, you may have an increase in libido, mood changes, anxiousness, and other hormonal-related changes.

If the egg is not fertilized during ovulation, then the egg will dissolve, and the process will begin the luteal phase.

Luteal Phase: Days 15-28

After the ovulation phase of the menstrual cycle, the empty follicle changes into the corpus luteum, which produces the progesterone hormone.

Progesterone helps prepare the body for pregnancy by thickening the uterine lining. A thickened lining makes it easier for a fertilized egg to implant in the uterus, to support a pregnancy.

If a pregnancy does not occur, the progesterone levels drop, and your period begins again, starting the cycle over.

During the luteal phase, you may experience fatigue, bloating, changes in appetite, and mood swings.

Trying to Conceive 


The decision to start trying to conceive should come with preparation. 


Dr. Crystal Acosta at CHRISTUS in Corpus Christi, Texas, highlighted the importance of maternal health before trying to get pregnant. 


“This means making sure all chronic conditions, such as hypertension and diabetes, are well-controlled and all chronic medications are safe for pregnancy,” Dr. Acosta said. “This way, their doctor can make necessary medication switches before pregnancy.” 


She said that well-controlled chronic conditions improve the chances of pregnancy and health outcomes for mom and baby. 


If you have decided to start trying to get pregnant, it is crucial to prepare your body with the proper nutrients before you start trying to get pregnant.


"I would emphasize the importance of starting prenatal vitamins daily, from the moment the decision is made to start attempting to conceive,” Dr. Acosta said. 


A prenatal vitamin should include a daily supply of folic acid, iron, calcium, vitamin D, and other essential vitamins. 

Timing and Fertility

The most fertile window for conception is typically the five days leading up to ovulation and the day of ovulation.

If you are trying to get pregnant, you should have sex around this time. You are most likely to conceive by having sex at least every 2-3 days leading up to ovulation, and the day of ovulation.

You and your partner should discuss this when planning to start a family. By tracking your menstrual cycle, you can identify your fertile days and increase the likelihood of successful conception.

How to Track Your Menstrual Cycle

  1. Manual calendar method: Mark the start and end dates of each menstrual cycle to identify patterns. After several months of regular cycles, you can identify the approximate phases.
  2. Period tracking apps: Phone apps that can help you calculate the phases of your cycle by inputting the start and end dates of your period. Many can also provide insight into symptoms, predict ovulation, and answer frequently asked questions.
  3. Ovulation predictor kits: These kits detect hormonal changes signaling ovulation, helping you pinpoint your most fertile days.
  4. Basal body temperature tracking: Measure your resting body temperature each morning before you get out of bed. You can use an oral thermometer or one designed for basal body temperature. Your temperature changes a bit throughout your cycle, with a slight increase right after you ovulate.

Trying to Conceive?

Find an OB-GYN

Navigating Irregular Menstrual Cycles

If you have a menstrual cycle that is shorter or longer than 28 days, irregular, or comes with severe symptoms, rest assured that you are not alone. Around 14% to 25% of women have irregular menstrual cycles. However, having an irregular period does not necessarily mean that you are infertile.

What if I have irregular periods? 

Experiencing irregular periods is more common than you may think, affecting many women at some point in their lives. Irregularities can manifest as cycles that are consistently shorter or longer than 28 days, or cycles with unpredictable variations.

Occasional irregularities are often normal and may be influenced by factors such as stress, weight changes, lifestyle adjustments such as diet, or hormonal fluctuations.

Does an irregular period mean I'm infertile? 

Having irregular periods doesn’t always mean you’re infertile. While regular menstrual cycles can make it easier to predict ovulation, women with irregular cycles can still conceive.

It’s important to understand your unique cycle and identify the signs of ovulation, which may require a bit more attention and tracking.

If you have an irregular cycle, you should talk to your doctor before trying to get pregnant. They can advise you on if you need fertility testing, or how to best track your cycle to predict ovulation for conception.

What are the signs of infertility in women? 

For most women, it is difficult to be diagnosed as infertile without being tested for various issues. The main symptom of infertility is simply the inability to get pregnant after at least one year of carefully timed, unprotected sex.

A short or long cycle or absent or irregular menstruation can be a sign of infertility, but many other conditions can cause these symptoms.

If you are concerned about your fertility, seek medical advice from your gynecologist or OB-GYN. Learn more about the signs of infertility here.

What causes an irregular period? 

Several factors can contribute to an irregular menstrual cycle. Hormonal imbalances, polycystic ovary syndrome or PCOS, thyroid issues, stress, extreme weight changes, and other medical conditions can all play a role.

Lifestyle factors such as excessive exercise or lack of sleep can also impact menstrual regularity.

If your irregularities are persistent, are in addition to other symptoms, or if you think they’re related to your inability to get pregnant, you should seek medical advice.

If testing is needed, your health care team can help you pinpoint the underlying cause.

How do I calculate ovulation for irregular periods? 

Tracking ovulation with irregular periods requires a personalized approach. One method is to pay attention to your body’s natural signs throughout your cycle.

Here are some ways to predict ovulation if you have an irregular cycle:

  • Monitor changes in cervical mucus, which tends to become clearer during your fertile window.
  • Consider using an ovulation predictor kit.
  • Keep track of your basal body temperature around the same time every day.
  • Manually log symptoms, temperatures, and patterns.

If you have a consistently irregular cycle or have difficulty getting pregnant, talk to your doctor about your options. Your doctor can conduct fertility assessments, which may include hormonal testing and imaging studies to determine the underlying cause. From there, your provider can provide guidance on the best options for you and your family.

Every woman’s body is unique, and an irregular cycle does not always mean infertility or health issues.

Regular checkups with a health care provider ensure proactive detection and management of any concerns related to menstrual irregularities. This helps pave the way for a more informed and confident journey toward pregnancy. 


Read Articles about Your Labor and Delivery Journey

A young woman is holding a glass of water and taking a prenatal vitamin.

Find the Best Prenatal Vitamin for You and Your Baby

Taking a prenatal vitamin is one of the best ways to help support a healthy and strong baby. Find out what the best prenatal vitamin includes.

Midwife vs. OBGYN: Understanding Your Choices for Childbirth Care

Explore the differences between midwives and OB-GYNs to make an informed decision for your childbirth journey. Learn about their roles, training, and how they contribute to your prenatal, delivery, and postpartum experience.

Cecilia’s Story

How an Unexpected Bump in the Road Led to Midwifery Care—and an Exceptional Birthing Experience

Essential Wellness Tips for New Moms

Discover essential strategies to support your physical, emotional, and mental health as a new mother.

3 Signs of Infertility in Men and Women

Learn more about the signs and symptoms of infertility in women and men. Trying to conceive can be challenging and often takes time. If you’ve been trying to get pregnant for a year or longer, you may have some questions about infertility.