Two sacs one smller no baby in it

Atlantis
I went for my first ultrasound today saw two sacs the smaller one mesuring 5 weeks and 5 days with nothing in it and the bigger one 6 weeks 3 days with baby in it. Neither had a heart beat just yet im scared of miscarriage of both if there is both. My doctor says it ealry and to come back in two weeks and we will look. Im trying to stay positive. Has this happen to anyone ?