Spider Bites can hurt for a day or so and then the spider bite should begin to heal after a week but after 6 to 8 weeks the spider bite should be fully healed.
If the spider bite hasn't gone away fully within 8 weeks or seems to get worse then you should see a doctor about it.
Also if the pain gets worse from the spider bite or you begin to feel ill after the spider bite you should go to urgent care to make sure you weren't bitten by a poisonous spider.