There are many different strands of flu that someone can contract. Usually, people will start feeling the symptoms first and then they will suspect that they have the flu. However, if you want to know which type of flu you have, you should go to the doctor. Then the doctor can determine which flu you have and a good amount of time that it will last. However, most common flus can last about a week and a half.
Although if you catch the first flu of the season, it will probably be the strongest case of the flu. If you got the flu after several others in your household have had it, then the flu will not be as strong and will most likely not last as long.
