Hello, I Was Diagnosed Last Week At 8w2d From LMP

Hello, I was diagnosed last week at 8w2d from LMP with a blighted ovum. This was after repeat scans at ten day intervals showed nothing inside the gestational sac. I was prescribed Misoprostol, which I took one week ago. I had some cramping and bleeding but not as much as I has anticipated and was concerned the miscarriage may be incomplete. When I went back today for my follow up ultrasound we were astounded to see the gestational sac is still there and inside it there is now a yalk sac, amniotic sac and fetal pole visible as well as possible pulsation. Although they told us it's unlikely to continue as a healthy pregnancy due to the slow growth, if it were to do so I'd like to know what effect the medication may have on the developing fetus.