Does it hurt when implanon is being inserted?

Minimal. This procedure requires a small stick and injection of a local anesthetic that does temporarily burn for a couple of seconds or so. After the anesthetic, the insertion of the Implanon device does not cause pain. This Implanon has now been replaced by the Nexplanon device. Check with your pcp/gyn . Fairly painless procedure and excellent birth control method for many. Reliable and safe.
Same as a vaccine. With implanon/nexplanon your provider will numb the skin first so you won't feel the insertion device go in. Maybe just some pressure as it slides in smoothly. It's a procedure that takes.