You can choose to mathematical methods such as Ogino-Knaus, the Billings natural or as basal temperature or biochemical tests to measure the hormone LH.
You're trying to get pregnant but no way. Have you ever stopped to think that maybe you're not doing at the right time?
To succeed it is essential you have sex during ovulation.

Here are a few tips and also two very efficient ways to get the most out of the days of the month that is idonoeo sex to get pregnant.

Ogino-Knaus mathematical method:

Also known as the rhythm method or the calendar method, the Ogino-Knaus method is a natural method of birth control. It was developed in 1924 by the Japanese gynecologist Kyusaku Ogino, and perfected by the Austrian doctor Hermann Knaus in 1928. Is to count the days of the menstrual cycle of women to achieve or avoid pregnancy.

Billings Ovulation Method:

This method is that the woman fertility monitors, identifying when it is fertile and not in each cycle. The flow of women is not always the same, but changes in quantity and consistency in the course of the cycle, becoming transparent, viscous, like egg white and becomes more elastic as you approach ovulation. This transformation is based on Billings method to determine the fertile days. Therefore, the couple abstain from intercourse practice in women notice an increased secretion of mucus and transparency.