Best if: You're breastfeeding; You don't want to get pregnant tomorrow; You've found your perfect family size
How it works: Your doctor inserts a flexible matchstick-size rod under the skin of your upper arm, where it secretes progestin for three years.
Perks: A convenient, low-maintenance option if you want to space out your pregnancies for several years or if you've completed your family. Because it contains progestin only, it may be a good choice for nursing moms (once your baby is 6 months old). It's also discreet: The implant is usually invisible beneath your skin.
Drawbacks: A doctor has to insert and remove the implant, and the procedure carries a small risk of complications (and you may scar). Your periods may be irregular, and obese women might need to replace it every two years.
Fertility returns 1 to 3 months post-removal.