Children under 18 should not take aspirin for influenza or suspected influenza. It can lead to an uncommon but serious condition called Reye's Synrome. Adults can take aspirin, but I prefer acetaminophen. Don't take more than the recommended dosage. I'm just getting over the flu and want to go back to work.
Influenza is most contagious at the beginning.
The shedding of virus generally stops by day 5 of the illness. You are contagious for 3-7 days after onset of the illness. There is a treatment that shortens the illness. Consult your physician for more information. It seems that every year we hear about different strains of the flu.