Did anyone have "marginal" Placenta Previa at their 20 week appt?

BabyC1

During my 20 week ultrasound they discovered my placenta is just partially covering my cervix.  Midwife isn't concerned (and neither am I) -- she said 99% of the time as your uterus grows, the placenta will move away from the cervix, so I'm sure that will be the case.  I have a follow-up ultrasound at 28 weeks scheduled to make sure my placenta has moved. 

 I'm just wondering if there is anyone whose placenta didn't move when they had marginal placenta previa???