As a woman in her mid twenties I'm hoping that some more experienced ladies might be able to offer their advice on or experiences of shunning contraceptive pills and devices in favour of a natural approach.

Unsatisfied with the prospect of spending the rest of my fertile life ingesting chemicals or using physical barriers I decided to check out the natural alternatives. In every other aspect of my life I try to live in such a way that the natural balances and processes are as uninterrupted as possible so I figured why should contraception be the only sticking point.

I have found a lot of useful information but I'd like to hear first hand from anyone who has put these methods into practice. It's also quite difficult to find info that isn't laiden down with biblical references. Not that I have a problem with religion or people talking about the impact their faith has on their life, but I would quite like to hear the opinion of someone who did it for reasons more along the lines of living naturally/pill free. 

So, does anyone have any experience of the Billings/ovulation method, sympto-thermo method, Creighton model or others?