6w scan, one gest one yolk sac two heartbeats???!

I am a first time mom and I just went for my first scan. I am lowkey freaking out…so scared to maybe have twins.

They found one gestational sac, one yolk sac, and two babies, two heartbeats.

Baby #1 HB is 118 Baby #2 HB is 125

I am having a hard time finding similar situations with one sac… any advice?

Stories? Good or bad… my next US is about two weeks away