The Doctor Prescribe Me To Have Northesterone To Stop My

the doctor prescribe me to have northesterone to stop my heavy periods because of the delay of 3 months.she prescribe me this for 21 days but on 18th day i got my period with cramps.is it normal?after my scan she told me i have very thick lining in my uterus and its not easy to get pregnant at this point as i wanted to get pregnant soon