I had mine done yesterday at 39+1 weeks. That is the earliest the doctor would do it and I asked for it. It's totally up to you and your preference, some people don't want to do it. It doesn't work the same for everyone, so don't be frustrated if it doesn't work. My belly is measuring 41 weeks and I'm 39 so I was worried about the baby getting to big to the point of tough labor or a needed c-section. We'll see if it speeds things along, fingers crossed! Good luck to you...