No, not immediately. The first time, nothing happened. The second week I got it and my water ruptured a hour or two later, I went to l&d and they were going to test the fluid to see if it was my water, when they did the swab test, my water broke halfway.
I had my membrane sweep October 1 at only 1cm dilated and immediately after I lost my mucus plug. Started getting mild contractions later that afternoon. Very early next morning I was getting contractions every 5 minutes I went in and they sent me home. Then on October 2 around 6:30 I was walking at the park and I thought my water was breaking I went in and it didn't but when he nurse checked me she broke it for me pretty much. So the sweep put me in labor the next day and I had my son early morning at 1:42 on October 3rd... Sorry probably too long of a story lol
Spotting is normal after a membrane sweep. With my first pregnancy, my water ruptured the second time I received it. It helps get your cervix to where it needs to be, helps you dilate but it isn't guaranteed to work.