The 4 Phases of Your Menstrual Cycle: What’s Normal and When to See Your OB-GYN
Your menstrual cycle is one of your body’s most important rhythms — and it’s more than just the days of your period. Your menstrual cycle phases have a lot of influence over your daily life. Throughout the month, shifting hormones influence your energy, mood, sleep, appetite, and how you feel from week to week. Feeling sluggish one week but energized and confident the next? Believe it or not, that’s likely your menstrual cycle. That could be due to your
Understanding the phases of your menstrual cycle helps you recognize what’s normal for you, anticipate changes before they arrive, and know when something is worth a conversation with your OB-GYN. Here’s a clear, practical guide from the women’s health specialists at Women’s Health Connecticut.
Key Takeaways
- The menstrual cycle has 4 phases: the menstrual phase, the follicular phase, ovulation, and the luteal phase.
- These phases are driven by four hormones — estrogen, progesterone, FSH, and LH — that rise and fall throughout the month.
- There are two distinct clinical phases: The follicular phase is the first half of your cycle, when estrogen rises and energy often peaks. The luteal phase is the second half, when PMS-type symptoms are most common.
- What counts as a “normal cycle” varies: A normal cycle runs 21 to 35 days, and some month-to-month variation is expected. Your own pattern matters more than hitting exactly 28 days.
- Start tracking your cycle to establish a baseline: Tracking your cycle for a few months helps you learn your baseline and gives your OB-GYN useful information.
- When to see your WHC provider: See your provider for periods that are irregular, very heavy, unusually painful, or missing, or for premenstrual symptoms severe enough to disrupt daily life.
What are the phases of the menstrual cycle?
Most people find it easiest to think about the menstrual cycle in 4 phases:
- The menstrual phase — your period
- The follicular phase — your body prepares to release an egg
- Ovulation — an egg is released
- The luteal phase — the lead-up to your next period
We’ve created the menstrual cycle chart below as an easy reference tool:
| Phase | When it normally happens in a 28-day cycle | What’s happening | Side effects |
| The menstrual phase | Days 1-5 | Your period | Usually low energy, mood swings, food cravings, and some physical symptoms |
| The follicular phase | Days 1-13 | Your ovaries are preparing to release an egg | Usually high energy, increased happiness and confidence |
| Ovulation | Days 14-15 | Your ovaries release an egg (typically lasts less than 48 hours) | You may feel your best these few days — high energy and confidence, no physical symptoms. Your resting body temperature (basal body temperature) may rise. |
| The luteal phase | Days15-28 | Hormones drop as if the egg remains unfertilized. | Usually mood swings, food cravings, low energy and other physical symptoms (including PMS) |
A typical cycle runs about 28 days, but anywhere from 21 to 35 days is considered normal for adults. Day 1 is the first day of full bleeding, and the cycle restarts when your next period begins.
One quick note on terminology: you may also see the cycle described in more clinical terms — the ovarian cycle (follicular phase, ovulation, luteal phase) happening alongside changes in the uterine lining (the proliferative and secretory phases). It’s the same process viewed from two angles. The everyday “4 phases” view describes what you feel; the clinical view describes what your ovaries and uterus are doing behind the scenes. This guide uses the 4-phase model throughout.
Hormones during the menstrual cycle
Hormones dictate so much of what happens in our bodies and nearly everything you experience across your cycle traces back to four key hormones:
- Estrogen: Builds up the uterine lining and drives the rise in energy and mood many people notice mid-cycle.
- Progesterone: Prepares the body for a possible pregnancy and dominates the second half of the cycle.
- Follicle-stimulating hormone (FSH): Prompts the ovaries to mature eggs.
- Luteinizing hormone (LH): Surges to trigger ovulation.
As these hormones rise and fall during the menstrual cycle, they shape the physical and emotional symptoms of each phase. When you understand the pattern, symptoms that once felt random start to make sense. Let’s dive deeper into each phase.
Phase 1: The Menstrual Phase (Your Period)
When: Days 1–5 (roughly)
What’s happening: This is your period, caused by your uterine lining shedding because no pregnancy occurred in the previous cycle. Estrogen and progesterone are at their lowest, and hormones are quickly shifting as your body prepares for a new cycle, so symptoms are common. Bleeding typically lasts 2 to 7 days.
Common symptoms
- Cramps in the lower abdomen or back
- Fatigue and lower energy
- Headaches, bloating, and tender breasts
- Mood swings, unexplained sadness, or irritability
Be gentle with yourself during this phase and take time to practice self-care. Rest, hydration, gentle movement like walking or yoga, and iron-rich foods can help you feel more like yourself.
Phase 2: The Follicular Phase
The follicular phase technically begins on the first day of your period and continues until ovulation — so it overlaps with menstruation at the start. It gets its name from the follicles in your ovaries: small, fluid-filled sacs that each contain an immature egg. During this phase, FSH prompts several follicles to develop, and usually one becomes dominant and matures toward release.
When: From Day 1 until ovulation (about days 1–13 in a 28-day cycle)
What’s happening: As follicles develop, estrogen rises steadily, rebuilding the uterine lining and lifting energy and mood.
Common symptoms
The follicular phase is often when people feel their best. As estrogen climbs, many women notice:
- More energy and stamina
- Sharper focus and motivation
- Brighter, more confident mood
- Less bloating as the period ends
Because follicle development varies from person to person, the follicular phase is the part of the cycle whose length varies most — which is a big reason cycles aren’t always exactly 28 days.
Phase 3: Ovulation
You may be surprised to find out that ovulation has a very short window. You have about ~6 days each month when you can get pregnant. And ovulation itself only lasts 1-2 days.
When: Around the middle of the cycle (about day 14 in a 28-day cycle)
What’s happening: A surge in LH triggers the dominant follicle to release its mature egg into the fallopian tube. Estrogen peaks around this time. The egg is available to be fertilized for roughly 12–24 hours, making this your most fertile window.
Signs of ovulation
Whether or not you are trying to conceive (TTC), it’s helpful to know the physical and mental signs of ovulation, which are:
- A change in vaginal discharge (often clearer and more slippery)
- A slight rise in body temperature
- Mild one-sided pelvic twinge or cramp
- Higher energy and sex drive
Tracking these signs is especially useful if you’re TTC — or trying to avoid pregnancy. Keep a note on your phone, or consider using a calendar or cycle-tracking app.
Phase 4: The Luteal Phase
What’s the luteal phase?
After ovulation, the empty follicle transforms into a structure called the corpus luteum, which produces the hormone progesterone. Progesterone maintains the uterine lining in case a fertilized egg implants. If pregnancy doesn’t occur, the corpus luteum breaks down, hormone levels fall, and your period begins — starting the cycle again.
When is the luteal phase of the menstrual cycle?
The luteal phase is the second half of your cycle — from ovulation until the day before your next period. In a 28-day cycle, that’s roughly days 15–28 (but remember, many women don’t have a 28-day cycle, so it varies). Unlike the follicular phase, the luteal phase tends to be more consistent in length from person to person, usually about 12 to 14 days.
Common luteal phase symptoms
As progesterone rises and then drops toward the end of this phase, many people experience premenstrual (PMS) symptoms. In fact, up to 90% of menstruating women say they’ve experienced PMS symptoms at some point.
Common luteal phase symptoms include:
- Breast tenderness and bloating
- Food cravings, especially for sweet or salty comfort foods
- Fatigue and trouble sleeping
- Headaches or digestive changes like constipation
- Mood swings, irritability, anxiety, or feeling more sensitive than usual
Everyone’s experience is different, and symptoms can vary from month to month. Regular exercise, steady sleep, balanced meals, and stress management can all ease luteal phase symptoms. If cravings hit, nutrient-rich snacks like nuts, fruit, or a small piece of dark chocolate can help.
Is my cycle normal?
This is one of the most common questions we hear — and the answer is likely yes, even if your cycle isn’t exactly 28 days.
Cycle length varies, both between people and month to month for the same person. A cycle anywhere from 21 to 35 days is generally normal for adults, and the follicular phase in particular can naturally run longer or shorter. Only about 13% of women have a 28-day cycle, so if you fall outside of that, it’s usually not a cause for concern.
What matters more than hitting an exact number is your own pattern — knowing what’s typical for you, and noticing any irregularities.
How to track your menstrual cycle
Because cycle length varies, tracking gives you a personal baseline and gives your OB-GYN useful information. Here are some tips to get started with consistent cycle tracking:
- Log Day 1 of each period (the first day of full flow) using a calendar or period-tracking app.
- Note your flow and how long bleeding lasts.
- Record symptoms — cramps, mood, sleep, energy, discharge changes — and roughly when in the cycle they appear.
- Give it a few cycles. Patterns usually become clear after about three months of tracking.
Over time you’ll be able to anticipate phases, plan around them, and spot anything unusual early.
When to see your OB-GYN
It’s normal to have some discomfort during your menstrual cycle, but there are certain signs and symptoms that mean you need to seek medical care. Reach out if you notice:
- Periods that are consistently shorter than 21 or longer than 35 days, or that become irregular
- Very heavy bleeding (soaking through a pad or tampon every hour or two) or bleeding between periods
- Severe cramps or pelvic pain that interfere with daily life
- Missed periods (when not pregnant) or a sudden change in your usual pattern
- Premenstrual symptoms so intense they disrupt work, relationships, or well-being — which can sometimes signal premenstrual dysphoric disorder (PMDD), a more severe form of PMS
These can be signs of conditions like PMOS (Polyendocrine Metabolic Ovarian Syndrome, formerly PCOS), endometriosis, fibroids, or thyroid issues — all of which are very treatable, especially when caught early.
A note on birth control and life stages
Hormonal birth control works by suppressing your natural cycle, so if you’re taking one, the phases we described may look different. For example, the “period” you have on the pill is a scheduled withdrawal bleed rather than a true menstrual phase.
Your cycle can also shift during perimenopause, after pregnancy, or with conditions like PMOS. If you have questions about what’s happening in any of these stages, your OB-GYN can help you understand it.
FAQ
What are the phases of the menstrual cycle?
There are four: the menstrual phase (your period), the follicular phase (your body prepares to release an egg), ovulation (the egg is released), and the luteal phase (the lead-up to your next period). Together, they typically span 21 to 35 days.
What is the follicular phase?
The follicular phase begins on the first day of your period and lasts until ovulation. During it, follicles in your ovaries mature and estrogen rises to rebuild the uterine lining. Because follicle development varies, this phase differs the most from person to person.
What’s the luteal phase, and when is it?
Mild weight loss in the first trimester from nausea and reduced appetite is common and usually harmless. Ongoing weight loss later in pregnancy should be discussed with your provider.
What are common luteal phase symptoms?
As progesterone rises and then falls, many people notice common “PMS symptoms” such as bloating, breast tenderness, food cravings, fatigue, headaches, and mood changes such as irritability or anxiety. These premenstrual symptoms vary from person to person and month to month.
How long is a normal menstrual cycle?
For adults, 21 to 35 days is generally considered normal, and some month-to-month variation is expected. If your cycle is consistently shorter, longer, or newly irregular, talk with your OB-GYN.
Questions about your menstrual cycle? Talk with a Connecticut women’s health specialist
Your cycle is a window into your overall health, but you don’t have to take a wild guess in the dark when something changes. That’s why we’re here — whether you’re tracking symptoms, trying to conceive, or simply want to understand your body better, our providers at Women’s Health Connecticut are here to help.
If you have questions about your cycle, notice a change, or just want a better understanding, request an appointment with your Women’s Health Connecticut Provider so we can connect you with guidance, resources, and support.