How to Track Your Period and Cycle: What to Log

To track your period, mark the first day of each period (day 1) on a calendar or in an app and note how long it lasts. Then add details like flow, symptoms, mood and energy. After a few months, you'll see your usual cycle length and patterns, and you'll have a useful record if you ever talk to a doctor.

Quick summary: Start with just the first day of your period. Add flow, pain, symptoms, mood, energy and sleep if you like. A paper calendar or an app both work; pick the one you will actually use. Tracking helps you spot patterns and changes, but it is not birth control.

Why track your cycle?

Tracking gives you information about your own body. It can help you:

• Know what's normal for you. The Office on Women's Health suggests marking the first day of each period for a few months to see patterns.
• Predict your next period and plan around it. Cleveland Clinic says tracking can help estimate ovulation and plan around periods.
• Notice changes. MedlinePlus says tracking each month can help you spot your usual pattern and any changes.
• Have a better doctor's appointment. The Office on Women's Health notes that irregular periods are easier to discuss with a doctor when you have records, and the NHS suggests that a diary or app record helps your GP see the pattern.

What to log

You don't need to log everything. Start small and add more if it's useful.

The basics - First day of your period (day 1) - Each day you bleed - Last day of bleeding

Flow and pain - How heavy it is (light, medium, heavy) - How many pads or tampons you use. The Office on Women's Health lists this as a useful detail. - Cramps or other pain, especially anything that makes you miss school or work

Symptoms, mood and energy - PMS symptoms such as bloating, breast tenderness, headaches, mood swings or cravings. See luteal phase: symptoms, moods and cravings. - Mood and energy levels - Sleep

Extras (optional) - Cervical mucus, which Cleveland Clinic describes as clear and slippery shortly before ovulation - Basal body temperature, which rises roughly 0.5 to 1 degree after ovulation and needs to be taken each morning before getting up - Medication or birth control changes, stress, illness or travel

How to work out your cycle length

Count from day 1 of one period to the day before day 1 of the next. Cleveland Clinic suggests counting the days between first days to get cycle length, and counting your marked bleeding days to get period length. See how long a normal menstrual cycle is for typical ranges.

Apps vs paper

	App	Paper calendar or notebook
Predictions	Can calculate cycle length and predict your next period	You work it out yourself
Effort	Fast taps, reminders	Needs a pen and a habit
Detail	Easy to add symptoms, moods and notes	Limited by space
Privacy	Depends on the app. Read what data is stored and shared.	Stays with you, as long as nobody finds the notebook
Cost	Many are free, some have paid features	Basically free

Cleveland Clinic notes apps can calculate cycle and period length automatically, and the Office on Women's Health says phone apps can help with tracking.

A few tips for choosing an app:

• Check how it handles your data. Look for a clear privacy policy that tells you what is stored, where, and whether it is shared or sold.
• Make sure you can easily delete or export your data.
• Remember that predictions are estimates, especially if your cycles vary.

There's no need to switch if you like paper. A simple calendar with an X on the first day of each period is enough to start.

What your tracking can tell you (and what it can't)

Tracking can show your typical cycle length, how long you bleed, and patterns in mood or energy. You may notice, for example, that you tend to feel more tired in the days before your period. That pattern is personal, and everyone's differs.

Tracking can also help you recognize when something is off, such as periods that are irregular, a late period, very heavy bleeding or severe pain.

What it can't do:

• Diagnose a condition. Records help a doctor, but they don't replace one.
• Prevent pregnancy. Tracking and fertile-window estimates are not birth control. The NHS says fertility awareness methods are 91 to 99 percent effective only when followed perfectly, dropping to 76 percent with imperfect use, and they don't protect against STIs. They can also take 2 to 3 cycles to learn.
• Prove a diet or workout plan works for you. Research on "cycle syncing" is limited and early, so use your log to notice your own patterns instead.

When to take your tracking to a doctor

Bring your records and talk to a doctor or nurse if:

• Your periods become irregular, with gaps under 21 days or over 35 days (NHS)
• Your period lasts longer than 7 days
• You soak through a pad or tampon every 1 to 2 hours
• You have severe pain or bleeding between periods
• You have no period for 3 months or more and you're not pregnant
• PMS symptoms affect your daily life. The NHS suggests keeping a symptom diary for at least 2 cycles to take with you.

A starter routine

1. Pick your tool: app, calendar or notebook.
2. Log the first day of your period every time.
3. Add a quick note on flow, pain and mood during your period.
4. Once a week, add a note on energy or sleep.
5. After 3 months, look back at your cycle lengths and symptoms.

Consistency matters more than detail.

Where Mochi Moon fits

Mochi Moon is a cozy iPhone app for tracking your period, flow, symptoms, moods, energy and sleep, with predictions, late-period heads-ups, reminders and a phase guide. Your data stays on your iPhone, with no ads or third-party analytics. If you want, you can share parts of it with a partner. Predictions are estimates and are not birth control.