placenta previa (almost)

Yesterday at my 20 wk scan the dr told me my placenta was low but not completely covering my cervix. So not quite placenta previa but close to it.  I have another u/s in 4 wks to check but in the meantime should I do anything different? The drs at the practice arent that helpful and are in and out so I wanted to ask here to those that maybe have more caring providers who spend more time and have some good advice.  Thanks!