Threatened miscarriage

So I went for an ultrasound today. According to the doctor I am 7 weeks. It was the first ultrasound her office has done. The tech was down right a bitch and would not say anything. She put me in an exam room and told me to wait for the doctor. The doctor came in and told me they can not find a heartbeat. She told me to come back in next week for another ultrasound. They did not take anymore bloodwork to measure my hormone levels. Leaves me feeling hopeless and worried. I do not know what to do. Should I find another doctor? Is there anything I can do?