If you've ever been diagnosed with a sexually transmitted disease like chlamydia, it's a good idea to get checked out by your doctor before trying to become pregnant. Most likely the disease will not affect your fertility, especially since you treated it promptly, but there's always a small chance that there could be some scarring of the fallopian tubes, which can make getting pregnant more difficult.
This scarring happens most often to women whose chlamydia went undiagnosed or was left untreated (it's usually readily cured with antibiotics), which can lead to a condition called pelvic inflammatory disease (PID). PID occurs when bacteria enter the cervix and spread throughout the reproductive organs. The main symptoms include lower abdominal pain, fever, backaches, and pain during sex.
If your doctor doesn't find any scarring after examining you, he or she will probably encourage you to try to get pregnant on your own for six months. If you don't conceive within that time, or if your doctor does discover some scarring, he or she may refer you to a fertility specialist.