Sonogram questions

Ana
I have my first sonogram this Friday at 7 weeks or so but the nurse told me last week when I went to my first nurse appt that most women get only two sonograms one at 7 weeks and one at 20 weeks and others only get more if there are issues. 2 sounds way too little for me because I believed you saw the baby's progress everytime you went especially at the 2nd trimester but since this is my first I'm not sure if it's just my doctor or if it's my insurance or how that is determined?