Marginal cord insertion

Any mamas have this? A month ago when I had my ultrasound they said everything looked great and I didn’t need anymore ultrasounds. After I left they called and said actually we need you in during third trimester. I asked why and they said just to look at the placenta and umbilical cord. Today during my appt I asked my midwife about the situation and she said that the umbilical cord is attached abnormally to the placenta. She said I’ll have to be monitored and have ultrasounds every 2 weeks in my third trimester. Has anyone had this in their previous pregnancies and can tell me their experience. Nobody I know has had this in their pregnancies.