Question!

Jodi

I’m almost 33 weeks and my ob has never measured my belly my last ultrasound was my anatomy at 20 weeks and she said my next one is at 36 weeks. I had anterior placenta but they wanted to me watch it for placenta previa, should I have gotten more ultrasound or had them measure my belly any? I started off at C-section then my last appintment 2 weeks ago they switched it to vaginally but idk how they could without seeing where my placenta is.