I was told in hospital with ds2 that if you breast feed every 4hr during the day and every six at night that it is 96% proof against pregnancy, and the midwife was pushing this sort of contraceptive, i questiond this and she shot me down and said it was right, now i feed every 2 hrs round the clock and my period returned at six weeks. for me i new full well that this was acurate but there where first time mums in there and a young girl as well and if they went along with this then they might have become pregnant again before they where ready