I got pregnant while on the mini-pill and EBF...so it isn't completely fool-proof. We also have a mama in my Nov
PR that had to go through IVF to conceive her twins and is now pregnant again. She didn't go on BC because she figured since it was so hard for her to conceive that her odds weren't likely. Your body can act differently as far as fertility goes after you have a baby so I wouldn't use breastfeeding alone as birth control.
We will be using mini-pill and condoms until we get the all clear when DH gets his vasectomy.