Does Absence Of Heart Beat In Foetus Cause Miscarriage?

Hello Doctor, Feb 8 is my first day of last period, I went for sonogram on March 30 , doctor said they are unable to detect the baby s heart beat and consider this as miscarriage . I do not have any cramping, bleeding or pain . Do I still need to consider this as miscarriage or wait for 1-2 weeks and schedule an ultrasound ? How safe is this condition? Do I need to keep any positive hope? Your reply is greatly appreciated ....thank you .