About a quarter of couples experience a period of infertility lasting more than a year, and some women miscarry before they even know they're pregnant. The most common reasons for infertility include hormonal problems and blocked fallopian tubes in women, and sperm disorders in men.
Your doctor will want to know about your development as a teenager and your periods. He or she will ask when they started, how regular they are, whether you've ever been pregnant before or whether you've ever had a pelvic infection or sexually transmitted infection.
It's also important to mention any other illnesses you've had and any medication you may be taking. Your doctor will examine you, including internally, and send you for blood tests to check your blood count and hormone levels.