There are some women who does not ovulate in spite of having regular period because of low progesteron hormone level in the blood in the second half of the cycle. Woman usually ovulates each month has a cycle length 28-30 days.
It is not very rare.
Women usually ovulates around the middle day of the cycle. If your cycle length 28 days you usually ovulate in 72 hours from day number 14. But women can ovulate any day of the cycle except during her period.
http://www.webmd.com/content/article/75/89900.htm
http://www.americanpregnancy.org/gettingpregnant/ovulationfaq.htm
CLICK HERE please for a positive FEEDBACK rating . Please click the green ACCEPT button if my answer is helpful to you. A bonus would be encouraging. If you need more help please feel free to ask. Take care.
Edited by vyetimyan on September 13 2006 at 11:29am