It means the placenta is in early stages which implies that you are in the first few weeks of your pregnancy. It is forming on the back of the uterus. It is grade 0 which means a young placenta. One end of the placenta is touching the internal os which indicates a low lying placenta but since not covering then not placenta previa. You will need specific guidance on exercises and other activities for the next few weeks as well as watch out for spotting or bleeding.