So my anatomy scan went great. I am 21 weeks today, the only concern was that my placenta is 3.3 cm…

So my anatomy scan went great. I am 21 weeks today, the only concern was that my placenta is 3.3 cm from my cervix! He wants to do a follow up ultrasound to make sure it moves up. Also he his head down. Is this normal?? With my first I never heard anything about my placenta and he was breech so this is new.