The short answer: a late period with a negative pregnancy test is very common and usually caused by stress, weight changes, exercise, contraception or a hormonal condition like PCOS or a thyroid problem. One late period is rarely a worry. See a doctor if you miss three periods in a row, or if a late period comes with other symptoms.
First: is it really late?
A normal cycle can be anywhere from 21 to 35 days, and it can shift by a few days from month to month. If you usually have a 30-day cycle, day 33 is only just late. Check your dates with our guide on how to calculate your next period.
Rule out pregnancy properly
Most home pregnancy tests work from the first day of a missed period. If you're not sure when your period was due, test at least 21 days after you last had unprotected sex. If your first test is negative and your period still hasn't come, test again a few days later. If that's also negative, the reasons below are more likely.
10 common reasons your period is late
- Stress. Exams, work pressure, a family crisis or a move can upset the hormones that trigger ovulation. If you don't ovulate on time, your period comes late.
- Losing weight quickly or eating too little. When your body doesn't get enough energy, it can pause ovulation to save resources.
- Being overweight. Extra body fat changes oestrogen levels, which can make cycles longer or irregular.
- Exercising much more than usual. A sudden jump in training, especially with low food intake, can delay or stop periods.
- Hormonal contraception. The pill, the contraceptive injection and the hormonal coil (IUS) can make periods lighter, irregular or stop altogether. The emergency pill can also make your next period early or late.
- PCOS. Polycystic ovary syndrome, now also called PMOS, is a common cause of irregular or missed periods. Other signs include acne, extra facial or body hair, and weight gain. Our PCOS diet guide covers how food can help.
- Thyroid problems. Both an underactive and an overactive thyroid can change your cycle. Tiredness, feeling cold or hot, and weight changes are clues.
- Breastfeeding. Periods often stay away or come irregularly while you're breastfeeding.
- Perimenopause. In the years before menopause, usually between 45 and 55, periods often become less frequent and less predictable.
- Natural variation and illness. Some people simply have irregular cycles. A bad infection or fever can also delay one cycle. Conditions such as diabetes can affect periods too.
How late is too late?
| Situation | What to do |
|---|---|
| A few days late, negative test, feeling well | Wait and track. Test again if your period doesn't come within a week |
| A week or more late, negative tests | Test once more. If still negative and it keeps happening, book a doctor's visit |
| Missed three periods in a row (and not pregnant) | See a doctor |
| Periods haven't started by age 15 | See a doctor |
| Late or missed period plus weight change, tiredness, extra hair growth, or very oily or dry skin | See a doctor, as these can point to PCOS or a thyroid problem |
| Positive test with heavy bleeding, severe one-sided pain, shoulder pain or fainting | Get urgent medical help |
What the doctor may check
Your doctor will ask about your cycle, weight, stress, exercise and any medicines or contraception. They may suggest blood tests for hormones, thyroid and blood sugar, and sometimes a pelvic ultrasound. Treatment depends on the cause. It may be as simple as lifestyle changes, or medicine to regulate your cycle.
Getting through the wait
- Keep a simple record of your period start dates, so you can spot patterns and share them with your doctor.
- Look after the basics: regular meals, enough sleep and gentle movement all support a steady cycle.
- Don't get caught out. A late period can arrive suddenly. Wearing a period panty while you wait means you're covered, and a panty liner is enough for light spotting.
Frequently asked questions
Can stress really delay my period? Yes. Stress affects the brain hormones that control ovulation, and it's one of the most common reasons for a late period.
How many days late is normal? A few days either side of your usual date is common. If you're more than a week late with negative tests, test again and consider seeing a doctor if it keeps happening.
I have white discharge but no period. Am I pregnant? Not necessarily. Discharge before a period and in early pregnancy can look the same. Read how to tell the difference, and take a test.
Can a late period be heavier when it comes? Sometimes. When ovulation is delayed, the womb lining can build up more, so the next period may be heavier. See how much bleeding is too much.
Related reading
- How to Calculate Your Next Period Date (With Examples)
- Period Came Early? 9 Reasons and When to Worry
- Discharge Before Your Period or Early Pregnancy? How to Tell the Difference
This article is for general information and doesn't replace advice from your doctor.
Sources: NHS: Missed or late periods, NHS: Doing a pregnancy test, NHS: Periods