About This Dream I Had

Today I woke up about five minutes before my alarm and lay there thinking, the whole time, about brown recluse spiders. 

Now, I've never met one, so there's no dramatic story here, but I did devote significant time to imagining how I might handle having one crawl across my sights. I thought about the story my acquaintance told: A classmate of hers at a Texas grad school was moving furniture when she found the bodies of three brown recluse - three - under a love seat.
Where is this coming from? I don't have a big fear of spiders, so is this the result of stress, which I've had a lot of over the last year? I keep thinking about it. Why brown recluse spiders? Why potential danger? Why now?
I spent about five minutes worrying about a poisonous spider I've never met.