Petite Abdomens

So I am 31w&4days with Di/Di girls ! During there growth scan they said their abdomens are small and a little below the percentile for them so they are gonna refer me to the hospital for a more in depth ultrasound to

Make sure they are getting good blood flow. Has any mommas experienced this ?!

Other than that the girls are doing great. Baby A is 3lbs 4oz and Baby B is 3lbs 6oz. Just worried and hope my little princesses are doing great !