Low Placenta?

Almost 11 weeks and high risk, so I see my OB every two weeks. On Thursday, I had another sonogram and doc said my placenta is overlapping my cervix, so no sex and to be super careful with any bumps or hits to the stomach. Now granted, I'm not too worried, but this on top of my already high risk pregnancy freaks me out. Anyone else have this issue? I've read it's fairly common and it should move up, but I also have a backwards inverted uterus, so she thinks that's the cause and it might not move? Helpful tips or stories please!