Baby and fluid measuring small at anatomy scan

Hello ladies.

I have a question. So I went to my anatomy scan last week and was 20w 3D. We had a hard time finding everything the tech needed to see and I was told baby was really low and we also could not find out gender. My doctor told me I am measuring 2 weeks behind and my fluid is low and wants me to have a level 2 ultrasound with MFM. I am scheduled to go tomorrow but I can’t stop thinking about my baby being small but I am trying not to worry. The heartbeat was 122bpm and strong. The baby is breech and laying sideways with his or her legs to the chest so we could not see between the legs. Has anyone been told their baby is measuring behind by 2 weeks and had a better scan with MFM?