Hello. I had an ultrasound at 20 weeks. The cervix was 40 mm, the norm…

Hello. I had an ultrasound at 20 weeks. The cervix was 40 mm, the normal range is from 80 mm. Blood flow in the left uterine artery increased. In the conclusion they wrote that everything is normal. The doctor never said anything, not once listened to the heartbeat, and doesn't react to complaints, only says "Take Elevit." That's all. It's my first pregnancy, I don't know what to do or where to go. I'm worried. Especially because her midwife told her while she was away that this is a sign of low amniotic fluid. What should I do?