my bitch (retriever) 2yo was mated accidentally by a dog 4 weeks ago, i took her to the vet for the morning after, she then finished her season as normal.  then 2 weeks ago she started bleeding the vet said this may happen, but now she has a thick creamy discharge which is kind of red too which i suspect is because shes still bleeding.  ive never had that before and wondered if it was ok, shes eating fine drinking her usual and is still her usual self.  should i be worried? i check her twice a day to see if anythings changed bur things are the same, shes due to stand from monday according to her usual pattern.  ive never had to get the morning after before and didnt know what was right the vet said it just reverses the season.  im quite concerned any help thanks

Any suspicious discharge should be examined by a vet as there is a danger of pyometra (infection of the uterus) which is life threatening and can progress with startling rapidity.
Just anechdotally it seems pyometra can often occur following an injection of this type.