Did anyone explore the options of natural birth control

I was wondering did any of you explore this option or know someone who failed or succeeded in this, just curious to gather some information and insight. I read a lot of articles on this subject and some say it’s useful others say it isn’t, I just think it would be interesting to hear someone’s personal experience with this. I think if this was truly effective no one would be using regular birth control pills due to all the side effects it has.