Girls, hi! Ultrasound in a week, but nerves are constantly buzzing, an…

Girls, hi! Ultrasound in a week, but nerves are constantly buzzing, and as it happens, the baby is not very active. How to calm down? Or understand in what case you really need to worry? I feel good, the tests are good. But, here the movements are unstable. Although I hear the heartbeat with doppler.