Most women immediately associate a late period with a baby on the way.  Although a missed period is really a reliable sign of pregnancy, you will find a number of reasons, other than pregnancy, for why your period may not arrive promptly.

The first step in determining in case your period is actually late is to calculate the duration of your menstrual cycle.  While 4 weeks is considered “average” for menstrual cycle length, cycles ranging anywhere from 21 to 35 days are normal and totally healthy.   To find out your cycle length, simply count the amount of days from the first day's a period before the day before you began the following period.  Some women’s cycles naturally vary a little from month-to-month, so it’s smart to count a few cycles to obtain your average and determine what is ordinary for you personally.

If days have passed since you expected your period to start and you’ve engaged in sexual activity that could lead to a pregnancy, then it’s a good idea to take an at-home pregnancy test.   Home pregnancy tests are sensitive enough to detect getting pregnant as soon as 4-5 days before your missed period, so a pregnancy test will be able to give you a definitive answer in case your period is late.  If, however, you’ve ruled out pregnancy just as one reason for your late period, then consider the following listing of the most typical reasons for a late period, other than pregnancy:

• Stress – Imagine you are being chased with a grizzly bear – would you favour your precious and limited energy go to your muscles in order to your reproductive system? Your muscles, of course… run!  Under stress, your amazing body is programmed to divert energy toward critical systems necessary for survival and from dispensable systems, much like your reproductive system.  Stress makes your body slow or stop the production of estrogen and progesterone, hormones required for both conception and menstruation.  Stress can be regarded as an acute threat, like this bear chasing you, or perhaps a chronic concern, such as a looming deadline on a very important project at work.
• Birth control – If you’ve recently changed your contraception, you'll be able to likely expect some changes in your menstrual cycle for at least a couple of months. Hormonal birth control, for example pills, patches, and rings, introduce synthetic hormones to your system that prevent ovulation.  Starting a new routine will almost certainly cause some irregularities inside your menstrual patterns.  Also, some oral contraceptives are delivered via three months of the active dose, accompanied by 1 week of inactive placebo pills.  If you are using this kind of birth control, then you need to only get your period four times each year.
• Certain Medications – In addition to contraception, many medications that appear unrelated to reproductive health can also impact your period. Antipsychotics, commonly used to deal with schizophrenia and bpd, can cause dramatic increases within the level of the hormone prolactin, which can suppress ovulation.  Antidepressants like fluoxetine plus some other SSRIs often cause an increase in menstrual period length, which would result in a late period.  Certain antidepressants may impact your cycle, so it’s important to talk to your doctor about negative effects you’re experiencing.  In addition to medications which are primarily used to treat mood disorders, some medications employed for cancer or epilepsy have also been proven to cause late periods or complete absence of periods.
• Extreme diet/exercise – Maintaining a very low body weight by following a restrictive diet or exercising excessively can prevent your body from ovulating. When body fat levels are incredibly low, your body enters a kind of starvation mode that may shut down reproductive function. In fact, studies of intense sports where leanness is rewarded, such as ballet and running, have reported that over 60% of female athletes cease menstruation during extreme training.
• Illness – It’s unlikely that the minor cold would significantly affect your period, but more serious illnesses such as the flu could definitely cause a transfer of your cycle. When you are getting sick, your defense mechanisms adopts overdrive.  This requires a lot of energy, so regular reproductive function can be compromised while fighting off contamination.
• Travel – Most of us are familiar with jet lag and the sleepiness that often accompanies travel across time zones. Jet lag occurs since your is accustomed to your home time zone, and for that reason releases hormones that regulate sleep/wake patterns according to that point zone – not your travel destination.  The sleep hormone melatonin may cause alterations in reproductive hormonal levels, so disruptions in your sleep cycle can impact your menstrual period.
• Irregular work schedules – Certain fields of labor, such as healthcare and aviation, often come with extremely variable work hours. Research studies in nurses and flight attendants (the second working in the same time zone throughout the study) have shown that giant variances within the hours that you work boost the likelihood of irregular periods.  Therefore, for those who have a job with rotating shift work, your cycle length might vary between months.
• Hormonal Disorders – Women with hormonal disorders are at a higher risk of having abnormal and irregular periods. Polycystic ovary syndrome (PCOS) is a common ailment that impacts approximately 10 % women, in which the ovaries develop follicles and release eggs at irregular intervals, thus causing irregular periods.  Just like fashionable as PCOS are thyroid disorders, which could also affect your menstrual period.  Hyperthyroidism, whenever your body makes too much thyroid hormone, can lead to shorter periods or complete absence of periods, while hypothyroidism, when your body doesn’t make enough thyroid hormone, can lead to more frequent and longer periods.  It’s critical to talk to your doctor about if you suspect you might have PCOS or any other hormonal disorder.
• Perimenopause – Menopause may be the absence of a period for 12 consecutive months. It typically occurs in women between 45-55, but more rare cases of early menopause have been reported by women within their 30s.  Perimenopause is defined as time surrounding menopause, often lasting for a few years.  During perimenopause, periods become irregular as ovarian function declines.