I agree, BFing can affect you falling pregnant. I never fell while BFing (BF DS for 2 years, AF returned at 9 months post birth). Sometimes it just takes a while to fall, for no reason at all. Keep trying, I hope it happens for you soon. If you aren' t already, maybe some close charting might make the difference. Temping and/or using OPKs to pinpoint O and make sure your LP (luteal phase, time between O and AF) is more than 10 days long. It's frustrating work TTC!!