How do you know what spider I was bit by?

You should know you've been bitten by the slight stinging.I've been bitten twice,and each time I saw the spider.No problems for me but others complain of imflammation at site.Both Spiders were male(small,about 25mm long).It could be that the female is the one that packs the punch.Others who have been bitten have told me they heat a needle and insert needle into bite site and no problems.