Here is one of the useful link for woman. This calculator calculate the most fertile days for a woman through online fertility calculator provided by the Department of Health and Family Welfare of Delhi.
Visit the link at http://health.delhigovt.nic.in/dynamic/fertilitycalculator.html
You’ll get the screen like this:
Users can calculate most fertile days by providing first day of last period in date, month and year format and average number of days in menstrual cycle.
Facility to reset the details is also available.
This is a rough indicator of the day of your ovulation. All other things being normal, there is a good chance of getting pregnant if you have unprotected sex during your fertile days.