Are ultrasounds dangerous or not?

I've seen videos and read information that ultrasounds damage your babies cells and can cause a miscarriage and even health problems for the baby later in life. I'm booked for a 6 week scan after having multiple chemical losses and now feeling like I need to cancel it because of this informationšŸ˜” does anybody have any positive information or negative experiences with ultrasounds? I just can't decide what to do for the best now I don't want to take any risks