welcome to HCM
your doctor has given it to regularise your period
its a contraceptive
so till you are continuing chance of getting pregnant is very low.
after your periods become regular , you can discontinue it under the guidance of your doctor.
it has side effects like intermenstrual bleeding
, post-medication amenorrhoea, changes in cervical secretions, aggravation of endometriosis
and certain vaginal infections like candidiasis