How many ultrasounds did/will you have in your pregnancies?

Ja
On Friday, I had my first scan done at 7w3d to rule out ectopic due to some pain I was having on my right side. Everything was fine and baby looked good. Saw the heartbeat 💗💗💗 This is my first pregnancy. 
My question is, how many ultrasounds are appropriate during pregnancy? There are some unknown risks of ultrasounds and though very slim, I don't want to over do it. My first actual appointment will be at 9w3d and I am scheduled for another scan then, but I'm thinking I may skip it and wait till the 12w scan.
Anyone have any thoughts about how many ultrasounds are normal for pregnancy?