Mid-credits there's a scene with Peter and Dana. After the credits there's a scene where Janine is talking to Winston at his work office, followed by him taking Ecto 1 back to the firehouse. The last shot is one of the containment unit with a light blinking.
Something that didn't make sense about the firehouse was that it looked like an abandoned firehouse but earlier in the film there was mention that it had been turned in to a Starbucks.