Marginal umbilical cord ?

So I have had 4 ultrasounds so far and it was never mentioned that I have a marginal umbilical cord .. meaning the cord isn't in the center of my placenta... but today I was told that they were/are worried about growth ... but today everything looks okay.. I'm 26 weeks and baby girl is measuring in at 2.1 pounds .. in the 64th percentile! !! Has anyone else had this and did everything turn out okay .. I have to go back for atleast one more growth scan at 30 weeks to check her progress ! Hope she just keeps on growing :)