I was in this group as well, lucky me LOL:
Less than 7% of women fully breastfeeding have their period when their baby is under 6mnths of age.
With Ds#1 - I had lochia for 6 weeks after birth at 8 weeks AF arrived, she came every 28 - 30 days after that, thank goodness I was wanting to TTC soon after birth, so it worked in well.
with DS#2 - I had a D & C at 6 days post birth, I thought this would delay AF for a while, wrong, she arrived back at 4 months post birth and was rugular after that until I made the big mistake off going onto the mini pill
