Feeling the same! I feel like early pregnancy is even more stressful than the IVF process … I think if you are able to pay for the scans there is no harm in doing them often. I already had a scan at 6 weeks/8weeks and one this week as well.
I had 4 scans and my 12 week scan is on 31st I’m still anxious. The private scan does comfort you, particularly on the day you have it but it won’t completely take away your anxiety x
With my first (IVF too) I kept a diary of my symptoms and it looks like they came and went. I know the feeling of anxiety. My advice to you is have faith, have fun and keep busy. Maybe book a 10 week scan as well?