Well, my friend is about to give birth to her 3rd child under 3 years old, so I'm going to go with BF is not a reliable source of BC.
I think you can take the mini-pill, but I had a Mirena and it was fabulous!
I would definitely not rely on BF as a BC method. My friend's brother is 10 mo. younger than her because that was the "method" her mom used.
I used the mini-pill after DD#1 and a few months after DD#2. I'm now using a Mirena IUD and am still BFing.