Your cycle changing from 28 to 31 days is usually normal variation, often due to stress, diet, exercise changes, hormonal shifts (like perimenopause or birth control), or even slight weight fluctuations, as cycles naturally range from 21-35 days, but persistent changes or missed periods warrant a doctor visit for conditions like PCOS or thyroid issues.
The average menstrual cycle lasts 28 days, however, regular cycles can last between 21 and 35 days. Stress, excessive exercise, and nutritional changes can all result in sudden shifts in cycle duration. Other factors include puberty, pregnancy, perimenopause, hormonal birth control, and health difficulties.
Perimenopause, the transition to menopause, typically starts in a woman's mid-to-late 40s, but can begin as early as the mid-30s or even earlier, and usually lasts for about four to eight years before menopause (the final period) occurs around age 51. Average onset varies, with some sources pointing to age 46, but it's a highly individual process, influenced by genetics and lifestyle.
Things like stress, a new workout routine, losing or gaining weight, or changing birth control can all impact your cycle. Call your healthcare provider if you miss your period for three or more months in a row or if you experience other unusual symptoms during your next period.
The length of the menstrual cycle varies from woman to woman, but the average is to have periods around every 28 days. Regular cycles that are longer or shorter than this, from 21 to 35 days, are normal. The menstrual cycle is the time from the first day of a woman's period to the day before her next period.
You are likely to be most fertile on the day of ovulation and during the 4 or 5 days just before ovulation. Studies have shown that to increase your chances of getting pregnant, you should have sex once a day or every 2 days during your fertile days.
See a GP if: your periods are irregular. your periods last longer than 7 days. you have irregular periods and other symptoms like weight gain, tiredness, hair growth on your face and dry or oily skin.
The most common reasons are:
What are the signs and symptoms of hormonal imbalance?
A stress period looks like menstrual changes due to hormonal disruption, featuring spotting, early/late/missed periods, heavier/lighter flow, longer duration, bigger clots, more cramping, worse PMS, and potential loss of libido, alongside physical signs like headaches, fatigue, muscle tension (neck/back pain), jaw clenching, and digestive issues, all stemming from elevated cortisol and disrupted reproductive hormones.
What are the symptoms of perimenopause?
We commonly see thyroid disorders, particularly hypothyroidism and hyperthyroidism, presenting with similar symptoms like weight changes and mood swings. PCOS, chronic stress, autoimmune disorders, and cancer treatments can also trigger menopause-like symptoms through hormonal disruptions.
Perimenopause, the transition to menopause, is often broken down into four overlapping stages focusing on menstrual cycle changes: the Late Reproductive Stage (slight cycle variations), Early Perimenopause (cycles vary by 7+ days), Late Perimenopause (cycles 60+ days apart, skipping periods), and finally, Menopause (12 months without a period), marking the end of perimenopause's hormonal fluctuations. Symptoms like hot flashes, mood swings, and brain fog can appear in any stage, though they often intensify in later stages as hormone drops become more significant, especially progesterone.
In addition, talk with your health care provider if: Your periods suddenly stop for more than 90 days — and you're not pregnant. Your periods become irregular after having been regular. You bleed for more than seven days.
In some cases, shorter periods can signal: Poor egg quality (diminished ovarian reserve) – As women age, egg quantity and quality naturally decline, which can shorten cycle length and reduce fertility. Hormone imbalances affect ovulation.
Menstrual cycles typically last between 24 and 38 days with some slight variation between cycles, which is normal. Significant disruptions or irregularities in the length of a period can be as a result of many different factors, ranging from stress and diet, to medical conditions and hormone disorders.
Hormonal imbalances show up as symptoms like fatigue, mood swings, weight changes, irregular periods, skin issues (acne), hair changes, sleep problems, brain fog, low libido, digestive issues, and temperature sensitivity, affecting energy, body functions, and mental well-being, often linked to stress, thyroid, or reproductive hormones.
Chemical messengers called neurotransmitters, which are in charge of sending impulses between nerve cells, are the main hormones linked to depression and sadness. In specifically, dopamine, norepinephrine, and serotonin are three neurotransmitters that are vital.
Common medical treatments for hormonal imbalances include:
Women start perimenopause at different ages. You may notice signs, such as your periods becoming irregular, sometime in your 40s. But some women notice changes as early as their 30s or as late as their 50s.
Here are 9 signs your hormones may be out of whack:
Common symptoms
8 Safe and Effective Ways to Induce Menstruation
Many different medical conditions can lead to irregular bleeding, breakthrough bleeding, or shorter cycles, such as: Being underweight or overweight. Pituitary disorders. Primary ovarian insufficiency (POI)