You should get a pelvic exam by a gynecologist every year, or until they tell you it can be further apart.
Up to age 30, you should get an annual pap test and over age 30, depending on which pap test they use, you may be able to cut that down to every two or three years.
Your doctor will advise you best because they know you better, your history and medication, your physical health. There are exceptions to the above, so your doctor is in the best position to tell you about proper intervals.