2 Gestational sacs

I was just reading my ultrasound report i am 8 weeks pregnant i done a ultra sound at 7 weeks 2 days saw babys hesrtbeat at 179bpm and saw baby but in the report she wrote she saw two gestational sacs and said possibility of Dichorionic diamniotic pregnancy is this normal what is this???? Does this mean it can be twins and is it unhealthy condition im soo scared please help has this happened to anyone?