Now I know they often don't. I had 2 sweeps with DD1. 1st defo didn't do anything and she was born 4 days after the 2nd. I'm due to have a sweep for DD2 on Tuesday. No one thinks it is going to work, and I'm booked in for an induction 3 days later. But, what I'm asking is, if it works, how long until proper labour starts? I appreciate that you never know - labour might have started anyway - but how often does it happen within say 24 hours? 48 hours?