Menstrual Health
Your Menstrual Cycle Explained: What's Actually Happening Each Week
Published May 15, 2026
By Dr. Anam Ghani, MBBS, MS (OBGY)
10 min read
Most of us were taught that a period is just bleeding once a month. But your menstrual cycle is so much more than that — every single week, your body goes through a carefully orchestrated hormonal shift that affects your energy, your mood, your skin, your appetite, and even how you feel about people around you.
Understanding what is actually happening can help you work with your body instead of constantly feeling confused by it.
Here is a simple, week-by-week breakdown of your menstrual cycle, in plain language.
What Exactly Is the Menstrual Cycle?
Your menstrual cycle is the monthly process your body goes through to prepare for a possible pregnancy. It starts on the first day of your period and ends the day before your next period begins.
It is controlled by four main hormones: Oestrogen, Progesterone, FSH (Follicle Stimulating Hormone) and LH (Luteinising Hormone). These rise and fall in a specific pattern throughout the month, and their changes are what drive everything you feel.
How long is a normal menstrual cycle?
A normal cycle is anywhere between 21 and 35 days. The average is 28 days — but that is just an average, not a rule. Your cycle does not need to be 28 days to be healthy.
What actually matters is consistency. If your cycle is regularly 32 days, that is normal for you. If it is wildly unpredictable — ranging from 20 days one month to 45 days the next — that is worth investigating.
Your Period
What is actually happening inside your body during your period?
Your period starts because your hormone levels — specifically oestrogen and progesterone — drop sharply. This drop signals to your uterus that there is no pregnancy this cycle, so the lining it built up starts to shed. That shedding is your period.
At the same time, your brain sends out FSH to start waking up a group of follicles in your ovaries. Each follicle contains an egg. Over the next few days, they compete and eventually one dominant follicle wins.
Why do I feel so tired and crampy on the first day?
On Day 1 and Day 2, your uterus is actively contracting to push out the lining. These contractions are caused by chemicals called prostaglandins — the same ones that cause cramping. Higher prostaglandin levels mean more painful periods.
The bleeding and cramping combined with the hormone drop can leave you feeling drained, emotional and low on energy. This is completely normal.
How much bleeding is too much during a period?
Normal period bleeding lasts 2 to 7 days and involves losing roughly 30 to 80 ml of blood in total — about 4 to 6 teaspoons.
If you are soaking through a pad or tampon every hour for several hours in a row, passing clots larger than a 50-paise coin, or your period regularly lasts more than 7 days — speak to a gynaecologist.
The Follicular Phase
Why do I feel so good after my period ends?
This is the phase most women do not know about — and it is the reason you probably feel like a different person in the week after your period.
As your period ends, oestrogen starts rising steadily. Oestrogen is the feel-good hormone. It boosts serotonin, improves your mood, sharpens your focus, gives you more energy and even makes your skin glow. Many women feel their most confident, social and productive during this phase.
This is also a great time for harder workouts, important conversations and tasks that need concentration — your body is genuinely at a hormonal high.
What is ovulation and how does it actually happen?
Toward the end of Week 2, usually around Day 12 to 16 (though it varies), oestrogen peaks sharply. This triggers a surge of LH (Luteinising Hormone), which causes the dominant follicle in your ovary to rupture and release a mature egg.
That moment is ovulation. The egg travels down the fallopian tube toward the uterus. It can be fertilised for about 12 to 24 hours after release.
How do I know if I am ovulating?
There are a few signs your body gives you around ovulation:
Cervical mucus changes
You may notice more discharge that looks clear and stretchy — like raw egg white. This is your body making it easier for sperm to travel.
Mittelschmerz
Some women feel a mild cramp or twinge on one side of the lower abdomen. This is the follicle releasing the egg.
A slight rise in basal body temperature
Your resting temperature rises by about 0.2 degrees Celsius after ovulation.
Increased libido
This is not a coincidence — your body is biologically primed for reproduction right now.
The Luteal Phase Begins
What happens to your body after ovulation?
After the egg is released, the empty follicle transforms into something called the corpus luteum. This small structure starts producing progesterone — and this is where everything shifts.
Progesterone prepares your uterus for a possible pregnancy by thickening the lining and making it warm and receptive. It also has a calming, slightly sedating effect on the brain — which is why many women feel a dip in energy and motivation in this phase compared to Week 2.
If the egg is fertilised and implants, progesterone keeps rising to support the pregnancy. If not, it starts to fall — and that fall is what eventually triggers your next period.
Why do I feel bloated, hungry and tired in the week before my period?
Progesterone slows down your digestion slightly — this is what causes bloating and that uncomfortable full feeling. It also raises your core body temperature and increases your appetite, particularly cravings for carbohydrates and sugar.
You may also notice your breasts feel tender or swollen. This is progesterone stimulating the breast tissue — completely normal.
Late Luteal Phase & PMS
What is PMS and why does it happen?
PMS — Premenstrual Syndrome — happens in the days before your period as both oestrogen and progesterone drop sharply. This hormonal withdrawal affects the brain's serotonin and GABA systems — the chemicals that regulate mood, sleep and anxiety.
Common PMS symptoms include irritability, low mood, anxiety, difficulty sleeping, headaches, food cravings, bloating and fatigue. For most women these symptoms are manageable. For some, they are severe enough to interfere with daily life — a condition called PMDD (Premenstrual Dysphoric Disorder) that deserves proper medical attention.
Is PMS normal or should I be worried?
Mild PMS is very common — up to 75% of women experience some premenstrual symptoms. But severe PMS that significantly affects your relationships, work or mental health is not something you just have to put up with. Effective treatments exist.
If you find yourself dreading the week before your period every single month, speak to a gynaecologist. There is a lot that can be done.
Why do I feel anxious or low in mood before my period?
The drop in oestrogen in the late luteal phase causes serotonin levels to dip. Serotonin is a key mood-regulating chemical in the brain. Lower serotonin means lower mood, higher anxiety and disrupted sleep.
This is a hormonal event — not a character flaw, not weakness and not in your head.
When Should You See a Gynaecologist About Your Cycle?
What does an irregular period actually mean?
An irregular period is one that does not follow a consistent pattern — coming too early, too late, too heavy, too light or not at all. Some of the most common causes include:
PCOS: Causes irregular or missed periods due to hormonal imbalance and disrupted ovulation. Read more about PCOS signs and diagnosis.
Thyroid disorders: Both an overactive and underactive thyroid can disrupt your cycle.
Stress: High cortisol levels interfere with the hormones that trigger ovulation.
Significant weight change: Both rapid weight loss and weight gain can affect your cycle.
Perimenopause: If you are in your 40s, irregular cycles may signal the beginning of the transition to menopause.
— Do not ignore these signs —
Which period symptoms should never be ignored?
See a doctor if you experience any of the following:
- Periods that last longer than 7 days
- Soaking through a pad or tampon every hour
- Severe cramping not relieved by painkillers
- Spotting or bleeding between periods
- No period for 3 months or more when not pregnant
- Periods that suddenly become much heavier or more painful than before
These can be signs of conditions like fibroids, endometriosis, PCOS or hormonal imbalances — all of which are treatable when caught early.
— A Word From Dr. Anam —
Understanding your cycle is one of the most empowering things you can do for your health.
When you know what is normal for you, you are better placed to notice when something changes — and to seek help before small problems become bigger ones.
At our practice in Gurugram, we see women every day who have been living with painful, irregular or confusing cycles for years, assuming it is just how things are. Very often, it does not have to be.
If your cycle is causing you concern — or if you simply want to understand your body better — we are here. Open seven days a week, including Sundays.
— Watch on YouTube —
Dr. Anam explains the follicular phase