Insurance... pffff

So my insurance says very clearly “Prenatal Care - 100% - no copay no deductible”. I purposely made sure when picking my insurance plan that this was the case and double checked with the agent. Imagine my surprise when I find out that their definition of prenatal care doesn’t include ultrasounds or visits without the word “prenatal” even though my visits so far have been coded with various obstetric words. And I was told that only three prenatal appointments are covered per year. Not sure what I did wrong in picking my plan. I was told all five options had the same maternity coverage. (Blue cross blue shield, btw)