hi, my last period started on 1st aug and two weeks ago i started experiancing cramps in my stomach , felt just like period cramps but with no blood . that lasted 3 days. and last week mon , tues, wed ive had cramps with clear discharge and pink blood. now the past 2 days i have had cramps with brown discharge. what could this be? my period is always 28 days and i have never had this before.