By Robin Elise Weiss, LCCE, About.com Guide
A late period can be worrisome.
Photo © Dreamstime
Nothing strikes fear into the heart of any woman like a missed period, unless she is trying to get pregnant. Am I pregnant?
Pregnancy is the first thing that we think of when our period is
delayed. But is pregnancy the only reason for people to have a late
period? Here are the 10 most common reasons that you missed your period:
If you have taken a pregnancy test and it is negative. Most tests advise you to wait another week and retest. If the second test is negative or if you have a good idea of why your period is missing, then you can and should call the doctor or midwife sooner for a physical exam. They may also do blood work and can sometimes prescribe medications to help bring on a tardy period, like Provera.
(Source : http://pregnancy.about.com/od/amipregnant/a/missedperiod.htm)
- Stress
Stress can affect many things in our lives, including our periods. Sometimes we're so stressed out that our body decreases the amount of a hormone (GnRH), which causes us to not ovulate or menstruate. Working with your doctor or midwife can help you figure out what you need to do to relax and get back on schedule. This can sometimes take a few months or more to work itself out. - Illness
A sudden, short illness or even a longer illness can cause your periods to be delayed. This is usually temporary. If you think this is the reason that your period is late, talk to your practitioner about when they expect your period to return. - Change in Schedules
Changing schedules can really throw off your body clock. This is particularly true if you go from days to nights at work or vice versa. If you frequently change shifts and notice a problems with regular cycles, then see if it is possible to be put on a more permanent shift or at least a shift that only varies after a lengthier time period. - Change in Medications
Perhaps you're trying a new medication and a delayed or absent period is the cause. Be sure to talk to your doctor or midwife about this side effect. It is very common with some methods of birth control. If you change medications, be sure to ask what effects this may have on your period. This is true, even if you don't think that there will be a big change. - Being Overweight
Carrying around too much weight can hormonally shift your cycles and even stop them. Most women will see a return to normal cycles and fertility with the loss of some weight, even if they are still considered overweight. - Being Underweight
If you do not have enough body fat you will not have regular periods, sometimes you can eve cause your periods to stop all together. This is called amenorrhea. Typically a weight gain will help you have your periods return. This is a frequent cause of a missed period in women who work out to an extreme or are professional athletes. - Miscalculation
The menstrual cycle varies from woman to woman. While we say that the average menstrual cycle is 28 days long, that is not true for everyone. Sometimes our period is believed to be late when in all actuality we have simply miscalculated. If you have irregular menstrual cycles, but know when you ovulate, look for your period about two weeks after you ovulate. That may help you keep an easier track of your periods. - Peri-Menopause
Peri-menopause is the period of time where you are transitioning from reproductive age to a non-reproductive age. Your periods may be lighter, heavier, more frequent or less frequent - but mostly just not normal. If you do not wish to get pregnant, be sure to continue to use birth control because you are likely to still be fertile at least some of the time. - Menopause
Menopause is when you have reached the point in your life where you will no longer ovulate or menstruate. Menopause can be a natural life event or may happen surgically through hysterectomy or through chemical such as various forms of chemotherapy. - Pregnancy
Finally! Yes, your missed period might be because you're pregnant! A simple pregnancy test can usually help you determine if you have missed your period because you are pregnant. The urine pregnancy tests and blood pregnancy tests look for the hormone hCG.
If you have taken a pregnancy test and it is negative. Most tests advise you to wait another week and retest. If the second test is negative or if you have a good idea of why your period is missing, then you can and should call the doctor or midwife sooner for a physical exam. They may also do blood work and can sometimes prescribe medications to help bring on a tardy period, like Provera.
(Source : http://pregnancy.about.com/od/amipregnant/a/missedperiod.htm)