I missed my period for 3 days . then when i got it , it was lighter than usual and its shorter only lasted 3 day normally it 5-6 days. no pain at all and i am sexually active but use condoms?

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 calling one’s primary care or Ob-Gyn doctor is a good idea if any symptoms are persistent, recurring, or worrisome.