Dear H.,
I was diagnosed with placenta previa at about 13 weeks and was put on bedrest at 15 weeks after an incident of heavy bleeding. After 5 weeks of bedrest, the placenta "moved" and I hard a normal, vaginal delivery. However, the OB who diagnosed my previa was sure I had a complete previa and scheduled me for a C-section at only 20 weeks. Fortunately, the previa had resolved by then, and the OB examining my ultrasound (not my original doc.) advised me to get right out of bed and start working out. Needless to say, I switched practitioners at that point. I had a normal, vaginal delivery and gave birth to a beautiful, healthy little boy. I DID have a retained placenta following my son's birth, but thanks to a very experienced, very persistent midwife, I was able to avoid surgery. My placenta was just a lemon all the way through!
Oh, and while I was on bedrest, some of my blood tests indicated a good possibility of Down syndrome. If you've had any bleeding, a false-positive for Downs is actually a decent likelihood, since the bleeding lowers your hCG levels, and low HcG is an indicator for Downs.
I hope that's helpful. I did a bunch of research on previas while I was on bedrest, so I may be able to answer additional questions if you have them.