Anak, 18 days ay matagal na para sa spotting, please go see your doctor as soon as pwede mo, okay? Hindi ko ma-diagnose yan online, pero kailangan talaga ng proper check-up para malaman kung ano ang nangyayari at ma-rule out ang anything serious. One of my mum friends had prolonged spotting din, at kailangan ng actual examination kaya please don't wait pa. Hugs, and go to your OB or clinic na agad!