It is so so common to have any type of spotting/bleeding in the first trimester of your pregnancy. The term used suggests to me that they'v just seen a bit of bleeding in your uterus which would explain the spotting. (? correct me if I'm wrong).
I had bleeding both pregnancies. My second pregnancy was gushing, running down both legs horror movie style type bleeding and DD was perfectly healthy.

I've found with ultrasounds that they have to list absolutely EVERYTHING they find even if it's no real risk. Thankfully, I never got ultrasound reports, they only ever went to the OB or GP who would from there inform me of any issues.

I hope that helps. Wishing you a stress free rest of your pregnancy