Forebag/bulging sac?

I am 37 weeks, more than 50% effaced and almost a full 3 dialted. Since I was checked earlier I have had a little bit of blood that filled a panty liner which I think is normal since getting checked earlier. I have had tons of pelvic pain and cramping as well as lower back pain. I was told today that the doctor could feel the bag under his head and I believe called it the forebag or a bulging sac and thinks that my water will break soon. Has anyone else had this? How long did it take for your water to break? Did you do anything to move things along?