It is very strange question because there are no fixed days for delay in periods. It can be late starting from few days to years depending upon cause. I am giving you some possible reasons of delay in pregnancy. Some causes are natural or physiological that need no treatments but some causes are medical and need treatment. Gap between 2 periods should be 26-32 days. More than 32 days and less than 21 days are problems. Following are some causes of delay or absence of periods.
1. Pregnancy
2. Breast feeding
3. Use of hormonal birth control methods
4. Certain medicines like antidepressants, oral corticosteroids
5. Stress
6. Chronic illness
7. Under weight
8. Thyroid problems
9. Tumors in pituitary gland
10. Excessive exercise
11. Hormonal imbalance
1. Pregnancy
2. Breast feeding
3. Use of hormonal birth control methods
4. Certain medicines like antidepressants, oral corticosteroids
5. Stress
6. Chronic illness
7. Under weight
8. Thyroid problems
9. Tumors in pituitary gland
10. Excessive exercise
11. Hormonal imbalance