Stress is a big factor, but you should take a test or go to a doctor because there can be other problems, such as ovarian cysts.

Stress, being underweightor loosing a lot of weight in a short time due to somethign such as Fasting. hormonal imbalances, certain womanly issues such as breast or cervical cancer. there are several things that can cause a late or missed period other than pregnancy. best plan is to go and see a doctor.

poly cystic ovaries. it happens every cycle if you have it.

it could be down to stress, dieting, polycystic ovaries, hormoal problems it could be due to a lot of things the best thing to do is visit your doctor. dont be embarrased because doctors deal with this all the time

Stress and anxiety (Most common cause) Excessive exercise Drastic weight reduction Hormonal imbalance (such as with polycystic ovarian syndrome) Also quite common Endocrine disorders Other illness Medications, including birth control pills and other contraceptives

G'day Anonymous, Thank you for your question. There are other causes for late periods other than pregnancy. These include: * breastfeeding; * stress; * medications including contraceptives; * hormonal imbalance; * polycystic ovarian syndrome; * malnutrition or anorexia; * thyroid problems; or * pituitary tumour (rare). For these reasons, you should see your doctor if your period is late. I have attached sources for your reference. Regards About Womens health http://womenshealth.about.com/cs/menstruation/a/lateperiod.htm Epigee Late period and missed period http://www.epigee.org/guide/lateperiod.html Menstruation Help I think I am pregnant http://www.menstruation.com.au/periodpages/help.html Womens Health http://www.womens-health.co.uk/late_period.html

I think keithold covered most of the possible causes. If you are concerned about a medical reason for late periods, please do see your doctor. If not, you might also benefit from some more knowledge about how your cycle can be delayed when nothing is medically wrong: The menstrual cycle can be broken down into two phases (pre and post ovulation). Day 1 of your cycle is the first day of red bleeding. Most women ovulate midway through their cycle. You may or may not notice increased vaginal discharge or pain in your side when you ovulate. The length of this first half of the cycle can vary by any number of days due to illness or stress. Your body can post pone ovulation (and pause your entire cycle). These delays can make a textbook 28 day cycler experience a long cycle of even 45 days or more and still be totally healthy! The length of the second half of your cycle will rarely vary by one than 1 day. If you don't have physical symptoms of ovulation, a basal thermometer can be used to take your waking temperature and mark the thermal shift that occurs after ovulation. The bottom line is that if you can determine when you ovulate, you'll always know when to expect your period without worry.