Last month and this month: I vomited (yellow bile), stomach ache, body ache, and low grade fever. And after 3 days, I feel always feel better.?

Difficult. Without more information it seems that you may simply have had two viral illnesses, but many other possibilities exist. If this recurs the best thing you could do is see your local doctor. Do you have gallstones?
Stomach flu. These symptoms sound most typical of a stomach flu. While it is not very common to get an 2-3 day episode two months in a row, it certainly can happen. It does not require any specific evaluation unless it starts occurring regularly every month. There is no specific treatment. Just rest, drink plenty of fluids, and practice careful handwashing to protect others.