Lo básico del ciclo
Tracking your cycle
Revisado: 4 de octubre de 2026
Solo en inglés por ahoraA simple record of your periods and symptoms helps you learn your own pattern and notice changes early. Here is how to count your cycle and what is worth noting.
Counting day 1 and cycle length
Day 1 of your cycle is the first day of period bleeding. Your cycle runs until the day before your next period starts. To find your cycle length, count the days from one day 1 up to the day before the next. For example, if one period starts on 3 March and the next on 31 March, that cycle was 28 days long. Your period length is the number of days you bleed, usually 2 to 7.
What is worth noting
Start with the basics: the day your period starts, how many days it lasts and how heavy the bleeding is. Then add anything that matters to you, such as cramps or other pain, headaches, bloating, sore breasts, mood changes, or changes in cervical mucus. Note any spotting or bleeding outside your period too. A short note about stress or other big changes in your life can help you make sense of an unusual cycle later.
Patterns matter more than one cycle
One cycle that is shorter, longer or heavier than usual can happen to anyone, because cycles naturally vary from month to month. A pattern over several cycles tells you much more. After a few months you can see your usual range, how long your periods last and when symptoms tend to appear. That makes it easier to spot a real change, such as cycles that become much shorter or longer, or periods that get heavier or more painful.
A sign of your overall health
Your cycle can reflect what is going on in the rest of your body. Long-term stress, big weight changes, thyroid problems and conditions such as polycystic ovary syndrome (PCOS) can all make periods irregular or stop them. Pain or bleeding that stops you doing everyday things is not something you have to live with, and treatment can help. A written record of your periods and symptoms can help a doctor or nurse find the cause of a problem.
Why predictions are estimates
Ciclo shows period predictions, estimated phases and a fertile window. These are estimates, not measurements. Cycle length can change from month to month, even in the same person, so a prediction can be off by several days. A prediction cannot confirm that you ovulated, and it cannot be used as contraception.
When to talk to a doctor or nurse
Get advice if your cycles are regularly shorter than 24 days or longer than 38 days, or if regular periods become irregular. Also get advice if you go 3 months without a period and are not pregnant or breastfeeding. See a doctor or nurse about bleeding between periods or after sex. Also go if a period lasts more than 7 days, or if painkillers do not help your period pain. Get urgent help if you bleed very heavily and feel dizzy or faint, or have sudden, severe pain in your lower tummy.
This is general information. App predictions are estimates; if your cycle changes or something worries you, talk to a doctor or nurse.