I have been BF for 15 months and no sign of AF yet. I would so like to TTC #3 but it seems I am going to have to wait. DD wants milk mainly at night and once during the day. I have heard of lots of women who have fallen PG while BF but it depends largely on the woman and when the body kicks in with hormones again. Some get AF early while BF and some wait until after 18 months. I think if you are supplementing you should get AF sooner rather than later. Good luck with TTC!