What Causes Bleeding After Taking Norlevo Emergency Contraceptive Pill?

i took a norlevo emergency contraceptive about a week and a half ago. yesterday i began bleeding, so assuming i was on my period, i started taking belara for the first time. the next day (today) the bleeding stopped, and i assumed it was just spotting and not actually menstrual period. Should i continue taking belara? what will happen to my regular period if i do?