[Bonny]

I'll chime in here as a mother of 4, have babies first then work on breast after you've finished having babies.  Pregnancy and breastfeeding causes a lot of changes in the body and breast, and any gains you make before having babies will potentially lost after pregnancy or breastfeeding or if your lucky you could experience increase in breast after pregnancy/breast feeding, while very rare it does happen (hormones are wonderful things).  So concern yourself with making a healthy baby first and when it's all over concentrate on nbe. 
Chrissy