My last period was june 3rd and ended on the 8th. two weeks after that i began to spot & it stopped for a few days. now today, im spotting again. i already took a pregnancy test last week & i was negative...what can be possibly wrong?

Irregular timing: of ovulation, is most likely reason, delayed or absent ovulation will cause you to be late. Of course even late ovulation can achieve a pregnancy if intercourse occurred at at time close to ovulation. See your doctor for testing and treatment, to correct ovulation issues. Polycystic ovarian syndrome/insulin resistance likely the cause.