4 wks 4 days ultrasound?

Mi
Hi Ladies,
I'm 4 weeks and 4 days pregnant and I had an early ultrasound today due to having some spotting. My Progesterone and HCG numbers are good, but the doc couldn't see anything on ultrasound yet. I'm a little worried because when I had my son we saw a sac at 4 weeks and 5 days. (This was with a different more high res ultrasound machine though) Has anyone else had this happen? I'm trying not to worry myself 😕