Should my doctor rupture my membrains?

I am 38 weeks and 2 days pregnant.. Im severly sick with a horrible cold. have back pain all the time.. and am really miserable.. my ultrasound tech said that the baby was 6 pounds and 4 oz in october.. and I have been having weekly ultra sounds.. but just recently stopped. I went to the ER the other night complaining of abdominal stabbing pains..and they said that I was 4 cm dilated.. I just want to know has anyone had their membraines scd or ruptured.. and does it hurt?? it this a good idea?