If ur perfectly healthy it's usually 2 to 3 depends on the dr. I had 4 with my 1st but I has preeclampsia. My second I had 3 . An my 3rd the dr was kinda rude I only had 2. This is my 4th an ive had a bunch but I'm high risk for preterm labor. I go for my 5th one on the 21st.
Depends where you live. In the UK it's usually 2: 12weeks for a downs syndrome check/dating and one at 20weeks for the anomaly scan.
I had 2
One to confirm the pregnancy, and one to find out the gender.
Varies by doctor and health