Late or irregular periods: causes, red flags and when to see a gynecologist
The cycle can be thrown off by stress, travel or weight changes — a single irregularity is not alarming. But if periods have been irregular for three cycles or more, very heavy or painful, book a gynecologist.
Common causes
- Stress, lack of sleep, intense training
- Rapid weight change and strict diets
- Hormonal shifts — thyroid, prolactin, polycystic ovary syndrome (PCOS)
- Starting or stopping hormonal contraception
- Perimenopause after 40–45
- Pregnancy — the first thing to rule out when a period is late
When to seek urgent help
Do not wait for a scheduled visit if you have any of these signs:
- Heavy bleeding — a pad an hour or more often — call 103
- Severe lower abdominal pain with dizziness and weakness
- Bleeding during a possible pregnancy
- Spotting after menopause
- A missed period with acute one-sided abdominal pain
Ambulance: 103 (103 from a mobile) · Unified rescue service: 911
Your specialist
Gynecologist
What to bring to the visit
- A cycle calendar for the past few months — an app or notes
- Previous ultrasound and hormone test results, if any
- A list of medicines and contraceptives
- Details of pregnancies and births
Frequently asked questions
How many days late is a reason to see a doctor?
First — a pregnancy test. If it is negative and the delay is over 7–10 days, or irregularities keep happening, see a gynecologist.
My period is late but the pregnancy test is negative — why?
The cycle can be thrown off by stress, a sudden change in weight, intense training, starting or stopping hormonal contraception, hormonal shifts — thyroid, prolactin, polycystic ovaries — and, after 40–45, perimenopause. If the delay continues, you can repeat the test; if it is over 7–10 days or irregularities keep happening, book a gynecologist. A late period with sharp pain low on one side of the abdomen is a reason to call 103.
Polycystic ovary syndrome (PCOS): gynecologist or endocrinologist?
Start with a gynecologist, who will examine you and, if needed, order an ultrasound and hormone tests. Hormones govern the cycle, so with PCOS, thyroid problems or high prolactin an endocrinologist may also be involved — the gynecologist will tell you whether you need one.
Light or heavy periods: when should I see a gynecologist?
Book a gynecologist if your periods have clearly changed: much lighter or heavier than usual, lasting longer, very painful, or with spotting between periods. If you soak a pad in an hour or less, or the bleeding comes with dizziness and weakness, do not wait for an appointment — call 103.
Which tests are done for irregular periods?
Tests are ordered by the doctor after an examination. They usually start with a pregnancy test, a pelvic ultrasound and blood tests for hormones, including thyroid hormones and prolactin; some hormones are tested on specific days of the cycle — the doctor will tell you which.
Can you have a period while pregnant?
There are no periods during pregnancy, but bleeding can still happen, and a doctor needs to find out why. If you might be pregnant, any bleeding is a reason to see a gynecologist straight away; with heavy bleeding or severe lower abdominal pain, especially on one side, call 103.
The information on this page is for reference only and does not replace a doctor's consultation. Only a doctor can make a diagnosis in person. If your condition worsens, call 103.