Viability scan---nervous

A
Friday at 5+1  weeks I had a bit of a red bleed in the morning so I called the doc and they had me go for blood.  My levels were 5400 which I think is good. The bleeding turned to brown the rest of the day and very light but then in the mornings I've had sight dark red bleeds but it turns to brown so im not sure what's going on. I suspect I have on of those subchronic hemotomas causing me to bleed, but I guess we'll see!
My doc told me to schedule a viability scan with a high risk specialist. Has anyone had one of these? Is it just a regular vaginal ultrasound? Will they take more blood? I'll be 5+5, so will they even be able to see anything?? I'm nervous and not sure what to expect.