If you've consciously been trying to conceive for about a year without success, or if you are over 35 and have been trying for about six months, make an appointment with a gynecologist for a check-up. You may want to start with a doctor who specializes in the diagnosis and treatment of infertility (How to choose the right fertility clinic?). Remember that matters of fertility are a complicated, and that the science is constantly changing, so not every gynecologist is a specialist in this area.