How they figure out the pregnancy?

The main symptom which makes an Iban woman aware of being pregnant (ngandong enggau nyera) is when she no longer has her menstruation. She is certain that she is pregnant if, during the following month she still does not have her period, she then begins to calculate her pregnancy as from the first month of her not having the menstruation. By the time the pregnancy is well along, she feels a longing for many kinds of food, especially for sour fruits.