Uhhh, did you get a look at this spider? Where abouts do you live in US ? Usually you wouldn't have much to worry about, but if it was a Brown Recluse, things could get nasty. If its been a couple days and its only getting worse, go see a doctor. It may be nothing, but its better to be safe.
Brown Recluse bites can lead to serious infections and massive tissue damage. Good luck








