I just recently had my 38th week appointment and my midwife said I'm dialed to a 2 and 75% effaced!…

I just recently had my 38th week appointment and my midwife said I'm dialed to a 2 and 75% effaced! She also suggested that she sweep my membranes at my next appointment to try and start labor. Anyone had this done before? What can I expect? I'm a little nervous!