I was at the Parentcraft center last Sat and the nurse was telling us that we can buy the Medela PIS a few days after birth when we are sure of a sufficient supply of breastmilk because of issues like blocked ducts, low milk supply... So till then also not late. Though she says to get the full set, instead of mini electric because the larger unit is more comfortable to use. Well I suppose most of us will want to BF our babies anyways, so sooner or later might not really bother us so much, and expressing milk for feeds has its benefits for those with no problems doing it.