Here's what I found on effectiveness of various methods.
Pregnancy Rates for Birth Control Methods

Frankly, that top number in the natural family planning box would be a bit too close to comfort for me. I've always heard my doctor make jokes and ask things like "What do you call people who use the natural method? Parents." Now I see why. I surely found myself wanting to know what their N (number) fields were that they took those high and low percentages from, didn't you? Temperature with condoms would probably be quite safe, and if you're willing to go that route, you and your husband are a lot more accommodating than Dave and I would be. We both hate the way they feel.

There are a lot of ladies here who love that Nuvaring. I don't know how it can affect libido, though. Maybe some of them will weigh in here on that. I'd be curious to know.

I haven't been taking the pill for years and have a diaphragm, which I don't use either. It's messy and troublesome when it comes to spontaneity, and frankly about half the time I get it gelled up just right and ready to put in, it springs out of my hand and goes flying across the bathroom like a little Frisbee. Having to wait till the next day to take it out is gross, too. So now I'm simply relying on the assumption that, at 45, I'm not at all likely to get pregnant. I know that's risky, but that's what I'm doing. I figure my poor little body knows it cannot support a pregnancy right now and isn't going to conceive one anyway.

Good luck! I'll be eager to hear what the other girls have to say.