Hallucinations!?

I'm 17 weeks tomorrow and when I go to sleep I "wake up" hallucinating. For example, I'll sleep and when I open my eyes I can see a spider above me or crawling on me and when I turn on my light or get up it's gone. It's been serval times it's always about spiders lol. So last night I was asleep and I felt myself wake up and look and saw a huge ass spider on my leg. So I watching it crawl away into the covers and for some reason I woke my boyfriend up and said:

"babe, there is a HUNTING spider on me"

Him: " what!?" Then he turned on the lights and nothing was there.

Then after five minutes he said

"What the hell is a hunting spider?" And I just busted out laughing because I must have been hallucinating again...

Basically does this happen to anyone else while pregnant?? Lol