What Are The Irregular Cramps And Brown Spotting?

IVE BEEN HAVING BAD HEADACHES FOR LIKE TO DAYS NOW ,IVE BEEN STOMACH CRAMPING LIKE MY PERIOD WAS ON WAS ON BUT ITS NOT.MY PAERIOD IS A LITTLE LATE.(BUT IT CHANGES ALL THE TIME) AND I HAVE THIS WHITE-BROWNISH DISCHARGE COMING FROM MY VAGINA ..PLEASE TELL ME WHATS WRONG