Everything You Need to Know About Ovulation

• Researched and written by: Dr Akshara CH, MBBS

• Medical inputs by: Dr Poonguzhali Liston, MBBS, MS OBG, FMAS, DRM, FRM, CIMP

• Medically reviewed by: Dr Yash Bahuguna, MBBS, MS, DNB, ISGE Certified Practitioner for PCOS

TL;DR

• Ovulation is the part of your menstrual cycle where your ovary releases an egg. 

• It happens once each cycle. You can estimate it by counting back about 14 days from your next period.[1] In a typical 28-day cycle, that’s around day 14. In shorter or longer cycles, the exact day will vary.

• Physical signs, such as cervical mucus, energy levels, and basal body temperature, often change around the time of ovulation.

• Tracking these changes helps you identify whether ovulation is approaching or has already occurred.

• It clarifies your fertile window and helps estimate when your next period may begin.

What Happens During Ovulation?

Ovulation is a short but important moment in the menstrual cycle. During the follicular phase, estrogen levels rise, stimulating the follicles, small sacs in the ovaries that contain immature eggs. The brain releases follicle-stimulating hormone (FSH) to help the egg develop. When the egg is ready, the brain releases luteinising hormone (LH).  

Research shows that the LH surge is what triggers the ovary to release an egg, which then moves into the fallopian tube. The egg stays viable for about 24 hours.[1] If it meets sperm in time and gets fertilised, it becomes a fertilised egg and begins its journey toward the uterus. If not, the body transitions into the luteal phase, where estrogen and progesterone prepare the uterine lining for a potential pregnancy before it sheds. 

When Does Ovulation Occur?

Ovulation usually happens about 14 days before your next period. In an average 28-day cycle, it usually occurs around "day 14". But a normal adult menstrual cycle ranges from 21 to 35 days. So, the timing of ovulation can shift depending on the length of your cycle.[2] 

• Short cycles (<21 days): Ovulation may occur earlier in the cycle.

• Longer cycles (>35 days): Ovulation tends to shift later.

• When cycles "vary a lot" (irregular cycles): Guidelines define cycles as irregular when cycle length changes significantly month to month or falls outside the typical 21–35 day range. In these cases, ovulation may be unpredictable or may not occur in some cycles, making calendar-based fertility window estimates unreliable.

FYI: What’s a fertile window? 

The fertile window includes the five days leading up to ovulation, the day of ovulation, and the day after. Sperm can live in the body for up to 3–5 days, while the egg survives about 24 hours. If you’re trying to conceive, having sex during this window helps ensure live sperm are already present when ovulation occurs, which improves your chances of pregnancy. 

Signs of Ovulation Day You May Notice

Your body often gives small cues in the days leading up to ovulation.[3] These signs may not appear for everyone, but they can help make it easier to track ovulation at home. Here are the most common signs of ovulation:

• Libido changes: A few days before ovulation, rising estrogen can lift your energy and sometimes bump up libido.
  

• Vaginal discharge: The high estrogen levels around ovulation influence the consistency of your discharge. You may notice your discharge to be clear, stretchy and slippery that may resemble an egg white.
  

• Ovulation pain: Some people feel a quick, one-sided pelvic ache, commonly called ovulation pain (Mittelschmerz), at the time of follicle rupture/egg release. Up to 40% of people who ovulate may experience this.[4]

• Temperature changes: After ovulation, when the progesterone levels rise, basal (resting) body temperature tends to go up slightly.
  

• Breast tenderness: Some may also experience breast fullness or tenderness in the days following ovulation, as hormone levels shift, leading into the luteal phase.

How to Track and Predict Ovulation at Home

Noticing signs of ovulation can give you a clearer sense of when ovulation happens, and tracking the ovulation cycle over time is helpful whether you're learning your menstrual cycle or trying to become pregnant.[3]

Cervical mucus observation

Slippery, stretchy discharge usually appears in the days before ovulation, the time when it's most possible to get pregnant, because sperm survive longer in this environment.

Tracking the menstrual cycle (calendar method)

Ovulation typically occurs approximately 14 days before the next menstrual period. However, this method works best for people with regular cycles. When cycles are irregular, ovulation timing becomes less predictable, making the calendar method less reliable on its own.

Ovulation predictor kits (OPKs)

Ovulation kits detect the luteinising hormone (LH) surge, which usually means ovulation will occur within the next 24–36 hours, giving you insights into fertile days.

Basal body temperature (BBT)

After ovulation, the hormone progesterone causes a slight rise in body temperature. This increase is usually about 0.3–0.5°C (0.5–1°F).[2] Because the temperature rise happens after ovulation, BBT does not predict ovulation. Instead, it confirms that ovulation has already occurred. Some wearable devices measure overnight or resting temperature. These tools can help detect the temperature shift that marks the transition from the follicular phase to the luteal phase. Like manual BBT tracking, they predict ovulation rather than confirm it.

Tip: Using more than one method, such as mucus plus luteinizing hormone (LH) testing, usually gives more precise results regarding your ovulation period than relying on a single sign, as individual differences occur.[3]

What May Affect the Timing of Ovulation?

Ovulation typically follows a schedule, but any disruption to the hormonal signals between the brain and the ovaries can alter its timing. These influences fall into three broad groups:

• Lifestyle: Lifestyle factors such as stress, illness, disrupted sleep, under-fuelling or sudden weight changes.[5]

• Health conditions: Underlying medical conditions, including PCOS and thyroid disorders.[6]

• Exercise: High training loads, especially when intense exercise is paired with low energy intake.[5]

These don't always prevent ovulation, but they can delay it or cause irregular menstrual cycles.

FYI: What prevents ovulation? 

Hormonal contraception keeps follicle-stimulating hormone and luteinising hormone (LH) low, so the process of ovulation never gets its green light. Guidelines note that combined hormonal methods reliably prevent ovulation when used consistently.[7]

When to Talk to a Doctor

Ovulation plays a crucial role in maintaining cycle regularity and fertility. Changes in your menstrual cycle or difficulty identifying ovulation while tracking can sometimes indicate that ovulation is irregular, delayed, or inconsistent. In these situations, seeking medical advice may be helpful. You may consider talking to a doctor if:

• Your previously regular cycle becomes irregular.
  It may suggest a new change affecting ovulation timing.[6]

• You are unable to identify a clear ovulation pattern even after tracking your cycles for several months.
  A lack of consistent signs, such as no clear temperature shift or irregular bleeding, may make it challenging to identify ovulation reliably.

• You have been trying to conceive for 12 months (or 6 months if you are over 35 years old).
  Difficulty conceiving can sometimes be related to problems with ovulation frequency or timing.

• You have symptoms suggestive of conditions such as PCOS or thyroid imbalance.
  These conditions can interfere with regular ovulation and menstrual cycles.[6]

Evaluation may include hormone tests, thyroid screening, or an ultrasound, depending on symptoms and clinical assessment.

Myth vs Fact: Understanding Ovulation Clearly

Bottom Line

Ovulation is a key part of your menstrual cycle, and your body typically provides subtle clues about when it's approaching. Most people ovulate about 14 days before their next period, but this timing can shift with conditions such as PCOS and thyroid disorders. Understanding your own cycle patterns and what affects them is often the most reliable way to make sense of your fertility and overall well-being.

FAQs on Ovulation Phase

When does my period come after ovulation?

Most people experience their period about 14 days after ovulation, which is why the length of the luteal phase remains relatively stable.

Can ovulation happen without symptoms?

Yes. Some cycles can feel quiet, which is why tracking tools are helpful.

Can someone ovulate twice in a cycle?

Very rare. You may have two hormonal peaks, but one egg release.

What is ovulation induction?

Ovulation induction uses medicines to help the ovaries release an egg in people whose bodies do not ovulate regularly or at all, often due to hormone imbalances or PCOS.

References 

1. American College of Obstetricians and Gynecologists. Abnormal uterine bleeding. Accessed December 8, 2025.

2. American College of Obstetricians and Gynecologists. Fertility awareness-based methods of family planning. Accessed December 8, 2025.

3. Owen M. Physiological signs of ovulation and fertility readily observable by women. The Linacre Quarterly. 2013 Feb;80(1):17-23.

4. Brott NR, Le JK. Mittelschmerz. InStatPearls [Internet] 2023 May 1. StatPearls Publishing.

5. Gordon CM, Ackerman KE, Berga SL, Kaplan JR, Mastorakos G, Misra M, Murad MH, Santoro NF, Warren MP. Functional hypothalamic amenorrhea: an endocrine society clinical practice guideline. The Journal of Clinical Endocrinology & Metabolism. 2017 May 1;102(5):1413-39.

6. Attia GM, Alharbi OA, Aljohani RM. The impact of irregular menstruation on health: a review of the literature. Cureus. 2023 Nov 20;15(11).

7. Faculty of Sexual and Reproductive Healthcare. FSRH guideline: combined hormonal contraception. Accessed December 8, 2025.