Good morning ladies, please help! I went to an ultrasound on February …

Good morning ladies, please help! I went to an ultrasound on February 3rd and there was one sac. I went back yesterday, February 24th, and they were two sacs. The doctor said I'm carrying twins and I'm 8 weeks pregnant. What worries me is that the other sac was bigger than the other, and the bigger one is empty while the smaller one shows something small inside. Do you think the bigger one will develop a baby or not? Is it too early at 8 weeks to see the fetus? The doctor said I must come back after two weeks.