Hi I Strtd My Periods On Wednesday Evening And I

Hi
I strtd my periods on wednesday evening and i am supposed to go away on Tuesday, i asked the doc for norethisterone n she said if i strt unknowingly i cn take a tablet straight away. So i took it. Despite having period pains
The tablet only worked on me for a day or two then on friday i strtd having severe period pains and had had spotting...now my periods are not normal! Im not bleeding how i should and im flying out on tuesday! Please advice me