How an ovulation calculator works

If you search online for an ovulation calculator or ovulation calendar, it seems there are so many, but at the end those I've seen are all very similar and, similarly, little reliable. They don't tell you much more than what you could guess by yourself. Your fertile days are around the middle of your cycle, you knew that, didn't you? Otherwise read here how to get pregnant.

The reason you can't really rely on an online calculator is that nobody can predict the future and this is what they try to do.

They show you a calendar, you input the date your last period started and the date of your two previous periods. So the calculator works out your cycle's average length and, by predicting when your next cycle should start, it predicts approximately when the ovulation is likely to occur, therefore when your fertile days are supposed to be. Some ovulation calendars even predict a few months in advance.

Why an ovulation calculator is not very accurate

But, as all women know, no two cycles have the same length, so it is impossible to know exactly when the next one will start.

There are many factors that affect the cycle length and duration, many women have very irregular cycles, some times the ovulation doesn't take place, other times there are two ovulations.

Another system used as an ovulation calendar was checking your temperature every day in the morning before getting up, for months. In fact, a woman's temperature rises slightly after the ovulation, too late for this information to be really useful. So, the concept behind this is that, by monitoring the pattern of your temperate from previous months, you could predict your next cycles pattern and therefore your fertile days, when the ovulation might occur.

Needless to say that this system too is very unreliable, especially if used for contraception.

So ovulation calendars that you find around the Internet are nice toys to play with or they can give you some information if you really have no clue about your fertile days. If so, read about your fertile days. However, if you want a more accurate and reliable calculator, that is, a way to know when you are most fertile, either because you do want to conceive a baby or because do not want, you'll have to use one of those fertility tests or fertility monitors that have been developed in recent years.

There are different types, depending on your purposes, some are for contraception, others for pregnancy purposes, but they use the same principles. Read on the next page.