I expressed about 3 bottles of colostrum between 36 and 40 weeks and only went into labour after a stretch and sweep. nipple teaking often doesn't work and if it does, bonus! if u do go into labour early they will give you a drug called niphetipine (sp) which is an anti spasmodic and does usually stop it. sometimes it works too well. Sarah tried to come 6 weeks early and the niphetipine made her go 9 days overdue