People who have had placenta abruption

I have an ultrasound Thursday and they are checking to see if I have a placenta abruption or placenta previa. I have been bleeding heavy for the last 5 days now. Baby is currently fine but I wanted to know for those whom have had an abruption how long did you bleed for before the fetus passed away?? I am really worried about this appointment and so far baby is growing good and heart beat is strong. Sorry for whomever have had to deal with this. I am currently 17 weeks