Faint brown spotting 3 days, period never came, feeling really tired and cramping but not my usual cramping, pregnant test negative, what's going on?

Pregnant?: Pregnancy must always be a consideration. Purchase a home pregnancy test to rule out pregnancy. If negative in one week, see your doctor.

Anovulation: It sounds as ifyou may have suffered an anovulatory period; one in which your ovary failed to release an egg. This temporarily disrupts your hormones and causes your cycles to become irregular. If the irregularity persists, see your doctor.