Placenta previa.

Has anyone had a c section due to placenta previa? If so what week was it done? I have one doctors in fetal medicine telling me before 38 weeks and anther telling me she (the obgyn) won't schedule it until after 38 weeks. Everything I read says it should be done at 37 weeks to be safe and prevent bleeding. This obgyn also tried to force me to sign a consent to have my tubes tide during the c section (I'm only 33 year old. This will be my 3rd daughter). She made me very upset and I don't really trust her opinion