Can a medical checkup detect if a person has been smoking or not and what if its been two weeks since the person has stopped smoking and then gets the checkup done then will it get detected?

Two weeks off smoking can definatly show in a Medical Check up. It takes 4 years to be off smoking to have a system that does not trace any issues of smoking. By 4 years your system will look like you have never smoked! (That's for real) !