When should you start using your TENS machine? The short answer is as soon as possible.
If you are being induced, it is ideal to place the TENS machine on 30 minutes before starting the process of membrane rupture or the administering of the Pitocin hormone. If you are in the earlier stages of induction, you can hold off, but if you start to feel contractions, it is best to place it on.
For spontaneous labour you can start using it once you believe you are getting labour contractions, if they fizzle out you can always take the electrodes off and keep them for when it starts up again.
If you don’t have access to it right away, you can still find the TENS machine, which will benefit you. It has been shown to be a bit more effective when started ASAP.