To have any idea if you may have a poisonous bite or sting you need to be sure what it was that may have bitten you. You say you think you may have been bitten. You need to be sure about the circumstances regarding this. If you saw a spider bite you then you need to determine what kind of spider it was. This can depend upon your geographical position. There are many different types of spider around the world, many of which are not poisonous to humans, though there are several types which are extremely dangerous. Your description is incredibly vague and from this it is not possible to work out if you have been bitten and, if you have, what by.
The best advice is to seek immediate medical attention in your local area. A local doctor would be able to advise you as to whether a bite or sting is infected, though they may need some information and a description of what it was. You describe a red line forming, this could mean it is just a simple matter of a flesh wound or a reaction to a venom carried by the creature.
All this is extremely hit and miss and with such matters there is always a risk and time is of the essence, so it is best to see a doctor as soon as possible.
The best advice is to seek immediate medical attention in your local area. A local doctor would be able to advise you as to whether a bite or sting is infected, though they may need some information and a description of what it was. You describe a red line forming, this could mean it is just a simple matter of a flesh wound or a reaction to a venom carried by the creature.
All this is extremely hit and miss and with such matters there is always a risk and time is of the essence, so it is best to see a doctor as soon as possible.
