How Can I Tell If Breastfeeding Is Stopping Me Getting Pregnant?

Is there tests that can be done or signs?
Answers of ‘stop breastfeeding’ not welcome!
Thankyou.

How Do I Go About Stopping Breastfeeding?

I’m planning on stopping breastfeeding my 15 month old daughter soon, but I don’t know how to go about it. I don’t know anything about it, so please forgive my innocence of the subject. Does it hurt? Am I likely to get overly emotional about it? Or do you think that maybe I should just wait and see if she loses interest in breastfeeding?
I only feed her at night to get her sleepy, and then again if she wakes up during the night. Please don’t give me lectures about her having created a dependancy on me to go to sleep, I know that this has happened.
I’m just after advice.
Thanks in advance