VIVID DREAMS 😳

I'm 6 days til AF, I have been super drained the last few days so I've been sleeping a lot. Last night I had a really vivid dream and I just took a nap today and had a SUPER vivid dream 😳😳 like I woke up with chills it freaked me out so badly.
I've read this could be a pregnancy sign, have you ladies had this happen?
I wonder why??