Ovulation: Signs and Your Timeline

Ovulation is the process of an egg being released from the ovary. For people who have regular monthly menses, ovulation occurs roughly in the middle of the cycle, but it is different for everyone. Ovulation can also be influenced by certain hormonal disorders, some thyroid disorders, and stress.  This article explains more about ovulation, including some of the signs and symptoms that ovulation is occurring, how understanding ovulation can help lead to or avoid pregnancy, and when to contact a doctor with ovulation concerns. 

Ovulation, as the American College of Obstetricians and Gynecologists explains, is when an egg is released from the ovary. For people with two ovaries, the egg can be released from either ovary.

There are two phases of the menstrual cycle, divided by ovulation: the follicular phase and the luteal phase. You can almost think of the two phases as “before” and “after” ovulation. 

However, the entire menstrual cycle encompasses the time when menstruation begins to the next period starting. The full menstrual cycle goes like this:  

1. menstruation
2. the follicular phase, which leads up to ovulation and can range from 10–16 days
3. ovulation
4. the luteal phase, which is relatively constant in duration and is usually about 14 days

In most people, the follicular phase can fluctuate, which can affect ovulation. However, no matter when you ovulate, the luteal phase remains the same. 

Ovulation guides the entire menstrual cycle. Each phase of the cycle is either preparing for ovulation or preparing for menstruation after ovulation has not resulted in pregnancy. 

If there are any problems with ovulation, either because of a temporary influence or an underlying disorder, it will make the menstrual cycle irregular. Without ovulation, a period cannot occur. 

Tracking ovulation can help you know if you should expect a change in your menstrual cycle. For instance, if you ovulate later than usual one month, you will know that your period may also start later than usual because the luteal phase — which is the phase after ovulation — is always the same length of time. 

Every menstrual cycle is a cycle of buildup to ovulation, then menstruation (if no egg is fertilized), then a buildup to ovulation again.

Everyone’s cycle is different, but, in general, a timeline for a regular 28-day menstrual cycle could go like this: 

• Days 1-7: Menstruation begins, estrogen levels are low, and follicle-stimulating hormone (FSH) levels start to rise.
• Days 7-13: The follicular phase begins, and estrogen, FSH, and luteinizing hormone (LH) levels rise.
• Day 14: Ovulation occurs, LH levels peak, and estrogen levels drop.
• Days 15-27: The luteal phase begins. Estrogen levels begin to rise mid-luteal phase, and then they fall with menstruation. FSH levels also start to rise in the late luteal phase.

Your menstrual cycle begins on the first day of your period, and then your hormones shift to build up to ovulation, and then they decrease if fertilization does not occur. After this, the process starts all over again.

The cycle is predominantly controlled by the levels of hormones rising and falling in your body. The primary hormones involved in ovulation are LH and FSH. FSH is what drives follicular growth, while LH triggers ovulation.

LH levels rise in conjunction with ovulation. Approximately 36 hours before you ovulate, LH levels “surge.” They will then peak 10–12 hours before ovulation happens. 

There are some physical signs that indicate that the body is approaching ovulation or that ovulation has already started. These include:

• increased energy and an overall feeling of wellness
• increased sexual desire
• breast tenderness and fullness
• a rise in basal body temperature, as your body temperature rises by about 0.5ºF to 1ºF during ovulation
• an increase in vaginal discharge that resembles egg whites, as it increases during the fertile window and peaks on the day of ovulation

Not everyone experiences clearcut signs that ovulation is approaching. Also, even among people who have regular cycles, ovulation can vary from month to month. 

This is why relying on the physical signs of ovulation can be challenging for people who use tracking as a primary form of family planning or birth control.

Ovulation is not typically painful, but some people do experience ovulation-related pain. For instance, a 2022 paper states that up to 40% of people who menstruate can experience a benign form of ovulation-related pain called mittelschmerz. 

This pain can range from mild to agonizing, and it can be felt on one side of the body in the lower abdomen. Ovulation-related pain generally occurs before ovulation, when the follicle prepares to rupture and LH levels rise. If you experience this type of pain, you will probably feel it every month.

Although mittelschmerz is benign, which means that it is not due to any underlying cause, there can be other reasons for ovulation-related pain that could be more serious. If you are regularly experiencing extreme pain at any point during your menstrual cycle, schedule an appointment with a reproductive health doctor. 

As the body approaches ovulation, there are several physical signs that indicate that ovulation is near. For instance, basal body temperature rises slightly after ovulation begins, cervical discharge increases significantly, and levels of LH peak about 10–12 hours before ovulation occurs. 

If you would like to track your ovulation, if you want to know when you are about to ovulate, or if you want to know if ovulation has occurred, there are several tools that you can use. These include the following.

Keep in mind that none of these methods are 100% accurate. This is because ovulation can change monthly, because everyone experiences physical signs differently, and because some of the tests can only identify when ovulation has already occurred.

This method requires you to check your resting basal body temperature every morning before you get out of bed, at about the same time every day. You can note down each day’s temperature or use an app to track the temperatures. 

Over time, when you detect a rise in your temperature, it is an indicator that ovulation has occurred. Planned Parenthood notes that most people’s basal body temperature is 96–98ºF (35.5ºC to 36ºC), but after ovulation, this rises to 97–99ºF (36–37ºC). 

You can purchase ovulation strips that work just like a pregnancy test. You urinate on them, and the strips will detect LH. Over time, these strips can detect trends in your LH surges and help predict when ovulation will occur. 

Some people may also choose to track their physical signs of ovulation approaching, such as noticing when their vaginal discharge changes.

A fertility monitor works with you inputting symptoms plus whatever measurements you choose, such as your temperature or physical signs. This software will help “learn” your cycle and detect when ovulation is nearing. 

There are many things that can either temporarily or permanently affect ovulation. For instance, even something like stress or travel can temporarily delay ovulation. Many people with menstrual cycles have probably noticed disruptions to their cycle in times of extreme stress, after traveling, or with an illness. 

Other things that can affect ovulation include: 

• diet
• polycystic ovary syndrome (PCOS) 
• thyroid disorders, such as hypothyroidism or hyperthyroidism
• structural problems with the ovaries or fallopian tubes
• endometriosis 
• sexually transmitted infections
• aging
• low body fat percentage
• primary ovarian insufficiency
• excessive exercise
• hormonal disorders, such as diabetes

Ovulation is necessary for someone to get pregnant. You can only become pregnant while ovulating or within 12–24 hours of ovulation occurring.

An egg and sperm must be present in order for fertilization to occur. Fertilization occurs when sperm fertilizes the egg that is released through ovulation, and this creates an embryo. 

The “fertile window,” which is when you are at your most fertile, is the 5–6 days leading up to and including the day of ovulation. This is the period of time when sexual intercourse is most likely to lead to a pregnancy.

To increase your chance of conceiving, it is best to have sex several times before ovulation occurs. During this time, it is generally recommended to have sexual intercourse every day or every other day, including on the day of ovulation during the fertile window.

Some people who have difficulty conceiving or have a condition that affects their ovulation may need some medical assistance to induce ovulation. 

There are different medications that a doctor can use to trigger ovulation. In some cases, these medications may also cause an ovary to release more than one egg at a time in order to increase the chance of conception. 

The American Society for Reproductive Medicine lists some of the medications used to induce ovulation. These include the following.

These drugs can lower estrogen levels, make the brain think that estrogen levels are low, or block estrogen from being produced. This tricks the body into thinking that estrogen levels are low, which stimulates FSH, which leads to ovulation. 

FSH does not lead to ovulation directly. It is, however, critical to the growth of follicles and the selection of a dominant follicle. Medications can trigger the production of more FSH, which helps follicular growth and eventually leads to the induction of ovulation.

These types of medication include: 

• clomiphene citrate
• aromatase inhibitors, such as letrozole and anastrozole

Insulin-sensitizing agents help lower insulin and certain sex hormone levels to promote follicle growth in order for ovulation to occur. They can be used on their own or alongside clomiphene citrate and aromatase inhibitors. Also, these drugs may be especially helpful in people who have diabetes, prediabetes, or PCOS. 

Insulin-sensitizing agents used to help induce ovulation include: 

• metformin 
• thiazolidinedione

It can be difficult to tell if you have a problem with ovulation, as ovulation is not always a clearcut phenomenon in the body. Everyone can experience ovulation signs differently, and some people may not even have obvious signs when they ovulate. 

In general, however, you should consult with a doctor if you are experiencing: 

• difficulty conceiving
• consistently irregular menstrual cycles
• periods coming less than 21 days every month or more than 35 days 
• fewer than eight periods per year
• no periods at all
• very heavy or very light periods
• any type of pain or bleeding with ovulation
• symptoms of PCOS, which can include:
  • excessive hair growth on the face and chin
  • weight gain and difficulty losing weight
  • thinning hair on the head
  • skin darkening under the breasts, groin, and neck
  • acne
  • skin tags
• any sudden, extreme changes in your cycle

Ovulation is the process of an egg being released from the ovary. Signs of ovulation approaching include an increased basal body temperature, vaginal discharge, and sexual desire. 

Once an egg has been released from the ovary, it lives for 24 hours. However, there is about a 6-day fertile window that someone who ovulates has to conceive. Sperm can live for up to 5 days in the reproductive tract. This means that if sperm enters anytime up to 5 days before ovulation occurs, pregnancy is still possible. 

Ovulation can be influenced by many different factors, from temporary changes such as stress or travel to more serious things, such as endocrine disorders or structural problems with the ovaries.

If you are experiencing severe pain, bleeding, irregular periods, or changes in your cycle, talk with your doctor.