Ultrasound found 2 sacs...

Ultrasound at 7 weeks found 2 sacs, one empty and the other with a baby with a heartbeat of 136bpm. Both are roughly the same size, sac with baby a bit bigger. Sacs are right next to each other. Dr said empty sac could be a non viable pregnancy or I'm hemorrhaging and wants me to go back Thursday for a second ultrasound to see if second sac is a threat to baby. I've had no bleeding, just a bit of spotting the week before I discovered I was pregnant. Thought it was implantation. Anyone ever experienced this? I'm freaking out that if I'm hemorrhaging it can come out and take baby with it??? Please tell me what to expect in both scenarios!