Terrified ;(

I'm about 5 and a half weeks(I think) pregnant with my second baby. Went for an ultrasound today and the sac looked healthy and uterus is thickening. Dr. Said everything looks great for my gestation, but we didn't get to see baby or heartbeat. I'm a nervous wreck 😭 I was farther along(6 and a half or 7 weeks) when I went in with my first, so we saw him and his heartbeat. Anyone else experience this?