Membrane sweep...

Wasn't really sure where to post this at, sorry if it's not in the right group. 
Due August 3, I'll be 39 weeks on Wednesday, and I have my check up on that day, doctor said if we haven't went into labor yet, we could try a membrane sweep that day and see if it could possibly jumpstart things. 
Just wondering if anyone has had this done, and if it worked, didn't work, what its like, etc.