It's Nature's clockwork, and for many women their menstrual period is as predictable as counting to 28 days. But when your period is late, does it mean that you're pregnant?
After ovulation, an egg can be fertilized and implant on the wall of your uterus to begin a pregnancy. If this doesn't happen, your period occurs as your uterus cleans itself out to get ready for a new cycle for the next month. But there are many reasons besides pregnancy to account for a missed period.
Age is an important factor in determining how regular your periods are. Young women who recently reached puberty may not have regular periods yet, and older women who are closer to menopause may experience irregular periods. Menopause occurs when you've not had a period for 12 consecutive months, but perimenopause can last from 6 to 10 years before menopause, and irregular periods can be a symptom.
Your weight can also affect the regularity of your periods. If your weight is either significantly lower than normal for your height, or if you are very overweight or obese, you may not have normal periods. Eating disorders such as bulimia and anorexia can also keep your periods from being regular.
Exercise may also impact on your menstrual cycle. If you've started a more-intense exercise regimen, this can make your period irregular. A significant change in your life routine can also cause you to miss a period. This could be a shift change at work that affects your sleep schedule, or even a major trip that causes jet lag.
Medications can also affect the regularity of your period. Antidepressants are one type of medication that can make you skip a period. Medical conditions can also be a factor; diabetes that is poorly controlled and irritable bowel syndrome are two examples of conditions that can cause irregular periods.
Some methods of birth control can also lead to irregular or missed periods. Some oral contraceptives, implanted birth control devices and birth control injections can make you miss a period. And after you stop taking birth control, you menstrual cycle can be affected for up to six months.
All of this may put your mind at ease, and a home pregnancy test can rule out the obvious, but if you experience irregular periods you should check with your doctor to see if there is a medical cause at the root of the problem.
