Can Placenta Previa With A Closed Internal Os And Echogenic Foci In The Fetus Resolve On Its Own?

Hi, In my 20 weeks anomaly scan, it has been found that I have placenta previa, which totally closed internal os with grade 1 maturity, can it be resolved by coming weeks and echogenic foci also found at the left ventricle of the fetus. I can t take bed rest as i am a working woman, My doctor suggested me to take susten sr 300 orally. I am much worried about my condition. Please help me with your guidence.