Are you saying the cat's behavior has changed since the dog was brought in? How? Is it hiding?
They will meet and mingle on their own terms. I'd be happy they aren't exhibiting aggressive behavior. Have they had a chance to sniff each other?
Have you tried holding the cat so that the dog can approach?
I'd give them at least 2 weeks. Longer, unless you really believe the cat is unhappy.
The cat might not like any dog you bring in. It's okay. They're not fighting. What about getting your cat another cat?
That's my opinion. I'm not a cat person though.