FAM method or natural family planning, Anyone do this?

Question

So I hate taking medication and that includes contraception. Taking something that stops your body doing a natural thing is scary to me and I often wonder why some women don't care a pop pills at will. 
I'm not currently in a relationship but I regularly wonder about birth control when I do get in a relationship. Anyway, I found the FAM method or as some call it the natural family planning. 
Has anyone tried this or currently do this to AVOID pregnancy? 
Have you had any unwanted pregnancies? 
Is it easy to do? 
Do you do it on paper or use things like the lady comp? 
Any information is welcome :)

Answer

My husband and I use it! Granted, it's been less than a year since I got off hormonal BC (awful), but it's worked so far. I temp to keep track of ovulation. We use a condom starting several days before ovulation and we stop 3 days after. Other than that we have unprotected sex. We could still end up pregnant if the condom fails or if I ovulate super early and unexpectedly one month (before we start with condoms), but otherwise, this method should work reliably. It's so much better than hormones! No side effects!

Answer

Also, any sex carries a risk of pregnancy. If you aren't willing/able to accept that, please don't have sex yet!