My period comes between the 18th-20th of the month. on the 18th i thought it was my period but it was brown and light bleeding. i had a few drops of blood the next day but now there is no period anymore. ?

It happens sometimes: Many women have occasional variation of their mucus discharge, some spotting between periods, a heavier period, a lighter period, a longer or shorter period, or even a missed period. Having one or two of these symptoms doesn’t necessarily mean there is a medical problem, but a pregnancy test (if having sex) and a visit to one's doctor are good ideas if symptoms continue or recur.