Placenta Previa

Hey ladies, at my dating scan the sonographer told me I had an anterior placenta but when I went for a private scan yesterday to find out the gender the sonographer told me I have a placenta Previa. She didn't say if it was complete, partial or marginal. My partner and I did a little research on it and have decided not to worry about it because it seems many of them move. I'm just wondering did anyone have this at a 16-20 week scan and it moved naturally? Thanks ladies X