Yolk Sac 12 Weeks

I had a private scan at 12+1, baby was moving, heartbeat was 163. The tech though said she thought she saw the yolk sac. She also said she saw the umbilical cord. Because this was private they didn’t measure baby or anything, although baby does seem bigger from when I saw them at around 10 weeks. Im freaking out now wondering why the yolk sac would still be there??