Sterility is investigated as a possible diagnosis when a women can’t conceive after one year of trying. You have been trying for 3 months so you should keep trying. You already have one child so even if you suffer sterility, it would be called a case of secondary sterility.

Lack of menstruation is the first sign of pregnancy but there are other conditions that can also cause lack of menstruation. A negative pregnancy test excluded pregnancy as a possible cause for lack of menstruation. Additionally, a miscarriage can cause period delay or lack of menstruation. After a miscarriage, the body needs a few months to establish a regular ovulating and menstrual cycle. Without ovulation, menstrual cycles are usually prolonged and irregular. Another often cause for lack of menstruation could be the persistence of a hormonally active ovarian cyst. In these cases, excessive hormone production (estrogen) prevents ovulation and the cycle becomes prolonged. When a cyst naturally dissolves, the hormonal levels drop and menstruation occurs. (But it's not a real menstruation because ovulation did not occur). If you suspect any of the above, you can schedule an appointment with your gynecologist for a consultation.