Anatomy Scan

I just got my anatomy scan scheduled for March 10th.  I know this is typically done around 18-20 weeks but on this day I will be 21w1d.  They are sending me to a high-risk facility for a better scan, so I'm unsure if that has anything to do with the delay.  I'm confident that they wouldn't schedule so late if there were any problems with doing so, but I'm curious if anyone else would try and get it rescheduled for sooner?