Placenta previa

Has anyone been told yet they have placenta previa? Or does anyone have experience from a previous pregnancy? When I had an ultrasound at 24 weeks he said it looks like I will have it but he wanted to wait until 28 weeks, do another ultrasound and then officially diagnose it in hopes that it will move over the next 4 weeks? Has anyone had their placenta move between 24-28 weeks or even later? I had a completely normal vaginal birth with my daughter in July 2014. But, I have had my left ovary removed byway of a laparotomy so I do already have an incision that would be that of a csection. I don't really care how my little lady gets here as long as she gets here safely but I was looking for stories from experience- the good bad and ugly! Thanks in advance!