A really small black spider?

I was in the washroom, taking a shower I live in Vancouver BC. I saw this really small spider no bigger than a small gravel. it was flat and it was completely black, it looked like a small black crab but than I saw it move with 8 legs. It was very slow I'm not very sure if it bit me or not, because I just got out and I stepped out grabbed my towel swung it a couple times than out of no where there it is. Also it's bite too small for me to probably locate where it is if I have been bitten. HELP I'M panicing I've watched so many weird videos on youtube on spider and I feel like they're crawling all over me right now, which they aren't.