Nothing on my ultrasound at 8 weeks. Help!

My last period was July 26th. I got multiple positive pregnancy tests starting August 21st. I have now missed 2 periods and have experienced pregnancy symptoms. I had my first ultrasound today and the doctor said I’m not pregnant and I should schedule a d&c. I am so confused as I have not had any bleeding. Do you think I should get another ultrasound just in case?