Did anyone have a scan at 16 weeks?

[nslw]

Someone I know had their 12 week scan, and has their 20 week scan booked. They are also having a scan tomorrow, at 16 weeks, on the NHS.

Isn't that unusual?
Or is there some reason I am missing?

I had scans every 2-3 as I have a short cervix due to previous treatment of pre cancerous cells. They were checking the cervix was shut and whether any stitches were needed to keep it shut.

Bleugh

*every 2-3 weeks