In the present scenario, you should go for the serum beta-hCG
test as your exact date of onset of menstruation
cannot be predicted in view of irregular cycles. This may need to be repeated after a couple of days if non-specific. You may also have a trans-vaginal sonogram. It is essential that you confirm/exclude pregnancy
so that further course of action can be decided. If pregnancy is excluded, you may need hormonal
therapy for inducing a withdrawal. Take care.