1. Flo - ovulation calendar, period tracker, and pregnancy app
  2. Your cycle
  3. Health
  4. Period

How Late Can a Period Be Before You Should Worry? 7 Reasons for a Delayed Period

If your cycle is generally regular, you might feel some concern if your period doesn’t come when you expect it to.

Woman having a late period holding a clock

Average cycle length 

 It’s not uncommon for periods to vary a little in length from month to month.  How late can a period be before you should worry? It can be considered late if it’s more than five days past due. 

Although a missed period can certainly make you worry, having an understanding of the menstrual cycle and of your body can help alleviate some of this stress. Here’s how the menstrual cycle works

Each menstrual cycle begins on the first day of your period and continues until the next period begins. The average menstrual cycle is about 28 days long. But a healthy cycle can be anywhere from 21 to 35 days long. Getting your period a day or two earlier or later is perfectly normal. 

Most periods last 3 to 5 days, but a period that’s 2 to 7 days long is also considered normal. A period that happens anytime of the month and is very unpredictable is considered irregular.

Track your health patterns with Flo!

Install our app to take control of your cycle and get customized health insights daily.

Reasons for late period 

Now that you’re familiar with what qualifies as a regular menstrual cycle, it’s time to understand why some women have late or irregular periods. During the early stages of puberty it’s common to have irregular cycles. It’s normal for adolescents to have irregular cycles for the first three years they get their periods. This is because the ovaries may not be releasing an egg every month yet, since hormone levels are still changing. However, if you are already past that phase and having late or irregular periods, there are lots of other things that can cause a late period.

Here are 7 common causes of a late period: 

1. Stress

Stress may be one of the most common reasons for a late period. There can be many types of stress, including:

Emotional stress caused by a death in a family, relationship problems, depression, or anxiety. 

Physical stress caused by surgery, injury, or illness such as viral or bacterial infections, diabetes, or inflammatory diseases of the gastrointestinal.

Some stress is a regular part of life. However, too much of it can disrupt your hormonal balance, which may result in a late or missed period. Proper stress management can be very helpful and includes things like meditation and exercise.

Stress management

2. Weight loss

Weight fluctuation is another common reason for a late or missed period. Being underweight can also prevent a person from getting their period. 

Rapid weight loss due to dieting or excessive exercise can also affect your hormones. The body needs time to recover after losing weight in a short amount of time. Being healthy and maintaining an active lifestyle can help your cycle become regular again.

3. Excess weight

Excess weight can affect when you ovulate by altering your levels of estrogen and progesterone. This can cause irregular periods.

4. Birth control

You can also experience a change in your cycle when you start or stop taking hormonal birth control. Birth control pills contain the hormones estrogen and progestin. These hormones prevent your ovaries from releasing eggs and significantly reduce the odds of becoming pregnant. They can also reduce the frequency of your period. For some people, it can take up to six months before their cycle goes back to normal after they stop using hormonal birth control. 

5. Polycystic Ovary Syndrom (PCOS)

PCOS is a fairly common condition that causes irregular periods. This condition causes your body to produce a higher amount of androgen, which is a male hormone. It also causes small cysts to form on the ovaries. In addition to irregular periods, common symptoms of polycystic ovary syndrome include: 

  • Weight gain
  • Acne
  • Body hair growth
  • Male pattern baldness
  • Headaches
  • Trouble sleeping

If you’re experiencing any of these symptoms in addition to late or irregular periods, a doctor can perform tests to make a diagnosis and recommend treatment.

6. Pregnancy

Pregnancy is another common cause of late periods. If your period is more than a week late, and you had unprotected sex anytime since your last period started, there’s a chance you may be pregnant. To find out, you can try a home pregnancy test, many of which can detect pregnancy even before your period is late. There is also a blood test that detects hCG in your blood and can be done even on the first day of the missed period. This test is performed by a doctor.

7. Early perimenopause

Menopause usually starts between the ages of 45 and 55. There are, however, women who begin perimenopause early, experiencing signs and symptoms at 40 and sometimes younger. This means that you are nearing menopause and will no longer ovulate regularly. People in perimenopause might still ovulate once every 3 to 6 months. 

When you should see the doctor? 

If your period is late, a pregnancy test can confirm whether or not you’re pregnant. See your doctor as soon as possible if you experience the following symptoms:

  • Unexpected heavy bleeding
  • Severe pain
  • Vomiting and nausea
  • Dizziness
  • High fever
  • Pressure in your lower abdomen

All women have different cycles which can vary in length from month to month. However, if you see or feel that something’s wrong, your doctor can help you understand the signals your body is sending to you. Tracking your period and symptoms in Flo is a great way to predict when your next period is due.

https://www.healthline.com/health/womens-health/why-is-my-period-late#see-your-doctor

https://www.healthline.com/health/pregnancy/causes-of-negative-test-no-period#medical-conditions

https://www.webmd.com/women/why-is-my-period-so-random#1

Flo Period & Ovulation Tracker

4.8, 279.7K
  • Amazing! Ricecake2003
    This app is super useful for tracking periods, and has given me mostly accurate predictions so far! I especially love that you can comment anonymously on posts and get help from and give help to the community.
  • Such an intuitive app! Hannah Malone
    I've tried several period tracker apps on the market and nothing is as good as Flo. It's accurate, detailed providing you with an abundance of parameters to log, and they even provide useful articles and surveys to help you better understand the complex nature of the female body.

Read this next

Track your cycle with Flo App

You will receive a one-time SMS. We will not store or use your phone number in any other way.