The third screening was done, the pregnancy is 32.1 weeks. Weight is 1…

The third screening was done, the pregnancy is 32.1 weeks. Weight is 1800. I'm not sure if this is normal? At the second screening they diagnosed low placental attachment. Now the baby wouldn't let us see anything on the ultrasound, it was almost an hour and every time we started doing the ultrasound he would wave his hands and feet, the doctor in disbelief, and now I don't know what to expect?