Yes, thats right, about the discharge about a week after kidding, and it lasts a few days, but clears up on its own. I assume you did not see this after around a week, or you would have called the vet then? I suppose there is no hard and fast rule about how many days after kidding, but all mine definitely had a bloody discharge the following week.
There again, you did the right thing calling the vet if your were concerned. If your goat is eating and drinking and seems ok, and the discharge is not smelling - I would be inclined to see how she goes on without calling the vet. Also, you will notice, that hay and straw etc. stick to the bloodied tail, just saying this in case you go in one morning and wonder what is stuck to her tail in a big lump!!