I started leaking at 24 wks and there was quite a lot. Like the whole front of my singlet would be wet/stained in the morning when I woke. I thought it was because my sac had totally ruptured and waters had broken when I'd gone into full labour super prematurely the week before. Perhaps it was just a coincidence? Gussy managed to stay put inutero for another six wks so I didn't need the milk at that stage...