Two sacs one heartbeat

So I started lightly bleeding red today around 2 pm and was able to see the dr at 4 pm. They did an ultrasound and I thought I was 7 weeks and 3 days but they said baby was measuring 6 weeks exactly and they saw a heartbeat. It looked like there was a second sac right near the baby with the heartbeat but they couldn’t tell if is was a sac that didn’t produce a baby or just blood. She did see blood trailing from about that spot to my cervix. Hopefully baby with heartbeat sticks! It has been a roller coaster day and I can’t figure out how to feel right now.