If My Dr Was Concerned About Placenta Membranacea And Having

If my Dr was concerned about placenta membranacea and having vasa previa at my 18 week ultrasound, what are the chances of the membranacea resolving? I was told the placenta still may move up and away from my cervix and was scheduled to have a recheck and second opinion in 2 weeks. I didn't think much about it until I saw my regular Dr 2 days after that anatomy scan and was told she is handing my case over to an experienced OB because I'm considered high risk. I'm having a really had time finding any kind of positive information that goes along with placenta membranacea, and after my Dr ditched me I feel very full of concern and worry.