Should I Stop Taking Norethisterone When I Noticed Brown Discharge And An Open Cervix?

Hi i started northistion 5mg to delay my menstruaation , tab is twise daily from yesterday wich was my 30th days of my cycle( my cycle usialy came at 33to 35 days of cycle) Ater 3dose of northistron i feel my cervis is open and i have brown discharge should i stoped the tab becouse if its my menstruation i stop my medication! Becouse i thout it will stop it!