A sweep is when a MW tries to sweep/stretch your cervix on or after your due date to try and get the baby moving. The cervix has to be "favourable" which normally means it's lower and is soft so she can do it. She basically inserts 2 gloved fingers up your foof, finds your cervix, inserts fingers and rolls them around the membrane there. If it works u can go into labour 12-24 hours later. I had one done on my due date on Monday but no baby yet. Was uncomfortable but not really painful.