Your menstrual cycle: length, changes and patterns

Cycle length, what can shift it, and how to tell the difference between a pattern in your records and a prediction about next month.

A ring of small discs, mostly lilac with short runs of sage and coral, crossed once by a ribbon.

5 min read Can stress delay your period? Sleep and exercise What evidence says about stress, sleep and exercise affecting your cycle, including low energy availability and when missed periods need checking.
5 min read How long is a normal menstrual cycle? Count your cycle correctly, compare NHS and ACOG ranges, and check when a short, long or changing cycle needs a conversation with your GP.
6 min read Irregular cycles: what to log and when to ask Keep a useful record when period dates vary, describe changes clearly and recognise when to arrange routine or urgent care.
5 min read Irregular periods: causes and when to see a doctor Common causes of irregular periods, from contraception to thyroid problems, with clear advice on seeing a GP and getting urgent help.
4 min read Period products, safe use and getting help with cost Compare pads, tampons, cups, discs and period pants, recognise urgent symptoms and find help accessing period products. Includes when to get help.
6 min read Periods after stopping the pill and other methods What to expect after stopping the pill, patch, ring, implant, hormonal coil or injection, including returning fertility and when to see a GP.
6 min read Recorded patterns vs predictions Learn what separates an entry, a pattern and a future estimate, with a worked example and practical ways to read your own record.
4 min read The hormones behind your cycle What oestrogen, progesterone, FSH and LH do, why cycle timing varies, and what evidence can support cycle-syncing claims.
4 min read Vulva and vagina: a plain guide The names for the external and internal parts, variation in appearance, gentle care and changes worth getting checked. Includes when to get help.

Written by the Veya team from the sources listed in each guide. They aren’t medical advice; if you’re worried about a symptom, talk to a doctor, nurse or pharmacist.