Many women have used fertility calculators when finding it difficult to conceive and have been successful! Believe it or not, a woman can only conceive 12-24 hours out of the month and usually the problem is simply bad timing.

So, how do you use a fertility calculator to get pregnant? Whether or not you decide to do it yourself with a calendar or use software available online, you will still need to know some very important dates and numbers. Most fertility calculators online ask you 2-3 questions and these questions are straight forward they must be accurate to calculate ovulation correctly.

You're most likely to be asked when your last period started, the number of days in your menstrual cycle and sometimes these calculators want to know information about your luteal phase.

If you regularly note down the dates of your period in your journal, this will be an easy exercise for you.  Then, all you need to do is count the days in between the dates your period starts.

What's a luteal phase?  It's the second half of your menstrual cycle that occurs once you have already ovulated.  It can last anywhere from 10 days to 16 days, and it's not as easy to work out, because you need to have an idea of when you're ovulating.

Fortunately it's quite rare to be asked about the luteal phase, as the majority of programs will only want to know the date your period started and your cycle length.

The ultra low tech way to get your fertile dates is to use your diary or pda, and enter your cycle start dates as a diary entry.  Then, all you need to do is subtract 14 from the predicted date of your next period, and voila - you have an ovulation date.  Of course, this is not accurate, so assume you might be fertile + or - a couple of  days of that date.

If you want to incorporate the luteal phase in your calculation, then monitor the daily changes in your cervical mucus as well as your BBT.  These two basic pieces of information can  really help the accuracy of your fertility calculation.

So now you know how to use a fertility calculator to increase your chances of getting pregnant. Keep reading, because in a minute, I'll share with you a link to a free fertility calculator that won't require you to enter information on your luteal phase.