I've had a lot of scans done, both during this PG and my previous one due to my history of m/c and autoimmune issues (I'd say over 10 scans each time). I have a quick (like, 1 minute) scan done at every OB appt and I have very regular appts. And yes, most of the u/s I've had done have been to 'reassure' me that everything is still going well with the baby. After 2 m/c, PG can be a stressful time for me and stress tends to trigger one of my autoimmune conditions which means a not so happy end to the PG. Having regular scans has been of huge benefit to me.

IMO if you need to a lot of scans then have them and don't worry about it. If you don't feel that you really need a scan done and are concerned about any risks then don't do it. Do what feels right for you.