Why is my period cycle a different number of days every month?
It's common for cycle length to vary by several days from month to month — a spread of up to about 7–9 days across cycles is within the typical range for many adults.
Resposta curta
Menstrual cycle length is counted from the first day of one period to the first day of the next. For adults, a cycle of 21–35 days is generally considered within a typical range; in adolescents, more variation is common. Stress, illness, significant weight changes, sleep disruption, and travel can all affect ovulation timing, which shifts the cycle length. Cyca's Insights screen shows your personal average cycle length (calculated from your last 6 logged cycles), your average period duration, and your variation (expressed as ± days) — giving you a concrete, data-driven picture of your own pattern over time. A variation of ±4 days or less shows as 'regular'; a wider spread is flagged as 'variable', which may be worth tracking more closely. If your cycle is consistently outside the 21–35 day range, or if it changes suddenly without a clear reason, that's worth discussing with a healthcare provider.
Try Cyca on a real example first, and check the current App Store listing for exact features and pricing before you decide.
O que verificar antes de escolher
- Cycle length = day 1 of period to day 1 of the next period (not from end to start)
- Typical adult range: 21–35 days; variation of ±7 days across cycles is common
- Ovulation timing shifts first — cycle length changes follow from this
- An app averages your recent cycles to make predictions; logging at least 3–6 cycles improves accuracy
- Consistently <21 days, >35 days, or sudden unexplained changes deserve a healthcare conversation
Um processo de decisão prático
- Defina a tarefa de que mais precisa no dia a dia.
- Teste a app com conteúdo real ou um cenário realista.
- Verifique as etiquetas de privacidade e os requisitos de conta.
- Confirme as opções de exportação e cópia de segurança.
- Escolha o modelo de preços que consegue manter com conforto.
Comparação rápida
| Necessidade | O que verificar | Porque importa |
|---|---|---|
| Modelo de preços | Verifique se as funcionalidades úteis exigem subscrição, um desbloqueio único, ou nenhum dos dois. | A app mais barata no primeiro dia pode não ser a mais barata ao fim de um ano. |
| Modelo de privacidade | Prefira o processamento no dispositivo quando o conteúdo é sensível. | Documentos privados, currículos, dados de estudo e conteúdos familiares merecem um tratamento cuidadoso. |
| Exportação / dependência | Confirme os formatos de ficheiro, a partilha, as cópias de segurança e os controlos de eliminação. | Uma boa app deve ajudá-lo a concluir a tarefa, não prender o seu trabalho. |
Onde o Cyca se encaixa
Cyca is built for exactly this — use the checklist above and test it on a real example.
PrivadoSem publicidadeNo dispositivo
Este é um guia de compra escrito pelo editor da app. Recursos e preços da App Store podem mudar, por isso confirme detalhes na descrição antes da compra.
Perguntas frequentes
How does Cyca calculate my average cycle length?
It measures the interval between each pair of consecutive logged period starts, filters outliers (gaps under 15 or over 60 days), takes your most recent up to 6 cycles, and averages them. Until you've logged at least 2 periods, it uses your manually-entered setting as the default.
What does the '±' variation number mean in the Insights screen?
It's the difference between your shortest and longest recent cycle length. A variation of ±4 days or less is shown as 'regular'; a larger spread indicates more variability in your pattern.
My cycle runs about 32 days — is that a problem?
Cyca is not a medical tool and cannot tell you whether your cycle length is clinically significant. A 32-day cycle is within the commonly cited adult range of 21–35 days. Any concerns about your cycle — length, regularity, symptoms — should be discussed with a qualified healthcare provider.