Incubation can be from 2 to 21 days. Late stage is nasty and obvious, but iirc, the patient is shedding virii before that point.
I read a very detailed description where the writer used lay-mans terms throughout. Explained the breakdown of the body ‘internally’....from tissue to cells and blood. It's far too graphic in description to bring here I think....but Ebola moves rapidly and hits pretty much ‘everything’...rather like a 'Purana' multiplying and working it's way thru the body.