the fact you're only feeding "occassionally" overnight i would say that it's a good idea to assume you have no "protection" from the BF. from my understanding, it only works as a contraceptive (if it works at all! lol) if you are feeding regularly 24/7.

AF returned for me naturally at 6.5 months when i was still feeding E very frequently.

if you're wanting to avoid any chance of falling PG now, i would definitely suggest alternative contraception for a while - but getting off the mini pill sounds like a great idea for you own state of mind.