An ovulation calendar can be a big help if you are trying to get pregnant. Using an ovulation calendar, you can figure out when you are most likely to conceive. Then you can try for a baby at that time.
Many websites offer a free online ovulation calendar but you can also create your own. You can either make a chart on squared paper or use an Excel spreadsheet.
Some of the most basic ovulation calendars will just give a prediction of your most fertile days based on the date of your last period. In the average cycle, ovulation happens 14 days after the first day of the last period. If you are just beginning to try to get pregnant you can figure this out for yourself very easily. Of course, you will need to remember to make a note of the date that your period starts every time.
However, we do not all have an average cycle. In reality, ovulation is the first stage in the monthly cycle, and the first day of the period begins around 14 days after that. So if you have a short cycle, you may ovulate very soon after your previous period ends.
If you want to be more accurate, you will need to create an ovulation calendar based on changes in your temperature during your cycle. The body temperature rises by 0.5 to 1 degree after ovulation.
So the first thing that you will need if you want to use this kind of ovulation calendar, whether it is online, on a spreadsheet or on paper, is an accurate thermometer that you can use to take your temperature each morning.
If you don't already have a thermometer, you will need to buy one. The easiest type to use is a digital thermometer. This way you do not have to try to figure out what the line of mercury is saying. You can pick up a digital thermometer at most drugstores.
Then you will take your temperature each morning before doing anything else. It's best to take it before you even get out of bed. After a few months, if your cycle is regular, you will know when you are likely to be approaching ovulation.
The best time to have sex is from about 48 hours before ovulation to 24 hours after. Sperm can survive for 2-3 days, so if you have sex a couple of days before ovulation there may still be sperm hanging out in the womb waiting for the egg. But the egg can only survive unfertilized for 24 hours, so any more than one day after ovulation will be too late.
This means that it is best if you can predict when you will ovulate. This is quite simple if the length of your cycle is the same each month. You can figure out when your next period is due to begin and count back from there.
It is more difficult if the length of your cycle is constantly changing because by the time you see the temperature change, you have only 12-24 hours to conceive. In this situation it is difficult to use an ovulation calendar. Other signs may be more useful. For example you may notice changes in your cervical mucus that will help you to know when ovulation is due.
Please be aware that an ovulation calendar is not accurate enough to be used as a reliable method of contraception.