The nightmare

It was night, I was sleeping and I thought I dreaming. In the dream I was sleeping in my room and I was looking at a shadowy/transparent ghostly non-human looking figure. I woke up in a panic, my dog was next to me and was unbothered. Until, a few hours later, I woke up her to barking at the door. My dog never barks. Never wakes up barking. Coincidence? I think not.