Missed twin at ultrasound

Sorry I keep posting but I’m determined my second babe is in there.

From the day I got a positive test, actually even before that I knew I was pregnant. With twins. Today that was confirmed. With the exact due date I got myself.

They saw baby one with a great HB of 173 and two yolk sacs but didn’t see baby 2. Any chance he or she was hidden? Anyone else have this happen?