Mine was covering the cervix at the 20wk scan, so low grade placenta praevia, and anterior placenta. Scan at 33 weeks showed that it had moved up, and it's now 6cm clear, which is awesome. There's not a lot you can do about it, but one midwife did recommend that I visualise it moving up, so I did.

I read a stat somewhere that 19 in 20 move. Good luck