How long does it take nexplanon to work? decided to get this instead of my depo shot that was due?

Per WebMD: The medication usually starts working right away when the rod is inserted during the first 5 days of your period. If your appointment is at another time in your menstrual cycle, you may need to use a non-hormonal form of birth control (such as condoms, diaphragm, spermicide) for the first 7 days after the rod is placed.

When switching from a shot to Nexplanon, it is recommended that Nexplanon be inserted on the day the next time a shot is due. The drugmaker says it will work immediately, and back-up contraception is not necessary. If deviating from the recommended timing of insertion, the woman should be advised to use a barrier method until 7 days after insertion.