Congratulations on your pregnancy.
In my experience, the very first nerves you get from scans, grow, change and develop into worry about movements, childbirth, your newborn and so forth!
My first pregnancy was a mmc. Saw a heartbeat at a scan and by the next scan, it'd stopped. I was completely shocked and distraught.
I fell pregnant again later that year and each scan had me in buckets of nerves. I actually had a panic attack at both my 7 and 10 week scans with nerves. However, that pregnancy now resulted in my now toddler!
I'm 7+3 in my third pregnancy and had a scan last Sunday, all was well. I'm already having anxiety about my next scan in 2 weeks time. Despite having a healthy pregnancy, the damage to my mental health from my miscarriage has firmly been done and the fear tends to outweigh the knowledge that I've also had a very normal pregnancy.
The short of it is, you probably won't lose the nerves and anxiety at any scan or waiting for the midwife to detect the baby's heartbeat at every appointment after 16 weeks. You just need to remind yourself that in all likelihood, you'll be heavily pregnant this Christmas, with family asking you when it's going to happen and you putting on a smile, whilst getting very fed up of the comments!!