If you've been on HBC, I'm guessing your cycles have already returned (at least in an anovulatory form). Under normal circumstances, you could likely (about 98% of cases, but there are some "lucky" ones who it doesn't work for) get 6 months or more of infertility out of breast feeding, but I wouldn't count on it given that you've added HBC into the mix. You'll be looking at some pretty weird cycles from the breast feeding, coming off the hormones, waking up at night to feed, etc, so as some of these mammas have pointed out, NFP/FAM is not going to be as easy as it would be other times. If your signs are obvious, that's great. If you need some help, there are a lot of expert charters on this site, and if it seems overwhelming, you might look for a teacher in your area that you can meet with to review your particular situation.