Ovulation generally happens approximately two weeks into the http://www.answers.com/topic/menstrual-cycle.
If your last menstrual period was May 13, your ovulation should have been approximately between May 26 and May 28, which is when you likely would have conceived.
February 13th, 1965 was a Saturday.
13th february 1972 was a Sunday.
February 13th, 1900 was a Tuesday.
February 13th, 1947 fell on a Thursday.
13th February 1988 13th February 1988 13th Febuary 1988
February 13th, 1994 fell on a Sunday.
February 13th, 1968 fell on a Tuesday.
February 13th, 1913 fell on a Thursday.
Before you can calculate your ovulation day, you must first determine, the date of your last period's first day and you need to know your menstrual cycle. This two information is needed in order for you to calculate your ovulation using an ovulation calculator. The date of your period is not enough information, to calculate ovulation.
Today is Friday the 13th, February 13th, 2009, that is!
Each woman has her own unique ovulation period. They can be tested through over the counter ovulation kits or by tracking a woman's cycle during a calendar month, starting the week after her period ends.