I get those too sometimes.
I had one that I woke up and my cat died. I was sad but at same time just too tired to deal with it, like, what can I really do right, but I knew the body would start to leak fluids so I moved her to the floor and gave her a last petting and was thinking I need to call the vet tomorrow and decide on cremation or w/e. Went back to bed. Woke up from the dream in relief that it was a dream, but cat was not next to me, so it had me a bit alarmed. Looked on the ground and she was in the same spot I left her in the other dream. I went to see her and her body was cold. Saddened that it was not actually a dream, I went back to bed. Woke up, and she was next to me this time and I touched her and heard "crrou" (funny sound she makes if I startle or wake her up) and was then relieved it was a dream. Weird stuff.
I get sleep paralysis sometimes too, that's kinda trippy. I want to try to exploit that, if you become aware of what's happening you can actually create and control a dream. I do sometimes realize that I'm dreaming when I'm inside a dream though. But usually when I realize it, I end up waking up shortly after. What's also kinda odd is when you're in a dream and realize that you're dreaming.