Gave birth just over 3 weeks ago and have so far lost a stone leaving just under a stone to go to get back to my normal weight. Bought some new scales but one day I was 10.9, the next day 10.7, the next 10.2 but then 10.7 again. Have I gained weight or could this be due to breast milk? Also how much weight should I expect to retain whilst breastfeeding.