What is up could i be pregnant?!!

Ive always been regular a 22 day cycle sence i was 11 with a 7 day period...well last month i got a extremely light 4 day bleeding an this month was the same light 4 day period...an im not sure if this is something to worry about but ive been pooping about 2-3 times a day and this morning is was bright green has this ever happend to you..if so did you turn out to be pregnant ??