In response to Pricillas question. The major component of preconception is making sure you have folic acid in your system. It is preferred that you are taking a multi-vitamin or prenatal vitamin with at least 400-1000 mcg of folic acid per day for 2-3 months prior to pregnancy. If you have a history of a baby with a neural tube defect you definately want to be getting the higher amount of folic acid the 1000 mcg dose. This is available as a rx as well.
Having a yearly exam is good too, but is probably less important than the folic acid. The yearly exam screens for cervical and breast cancer as well as evaluating weight, blood pressure, bad habits such as smoking and lack of exercise that may put your future pregnancy in a riskier category. It is always better to start pregnancy healthy with a normal weight and blood pressure if preferred and to have already stopped smoking. We can't stress the need to stop smoking enough.
Any doctor, nurse practitioner, nurse midwife, etc. is just fine to do a regular yearly exam and hopefully remind you of of the above listed considerations. Good luck!