If I thought I had Black Widows in my house I don't know that I could go inside at all, let alone sleep there.
I've got black widows in my house, and I don't worry. They're much MUCH more scared of you than you of them. With good reason. They're very very reclusive, and would much rather hide than fight. They love to lurk under stairwells, in hollows in bushes, in hollows in stone walls, places like that. And, in attics, too.
California is full of them. If you're concerned you can give your place a once-over. Usually I leave them alone, but sometimes, I'll feed some to the lizards.
They won't really hurt you if you don't let them crawl on you, which they're usually loath to do.
I really wouldn't spend the money on exterminators for spiders. They do so much to keep bugs you don't like under at least some control, they're worth the very nominal risk to have around. Indeed, they ameliorate the need for exterminators, often.
I don't think they're as common in Canada as here, but I'll let Canadians confirm or overrule me on that point.
Not meant to be rude, please. Just trying to reassure! :vs_cool: