Is It Safe To Have Hormone Injection Treatment During Periods?

i have taken primolut N FOR THE past 10 days .I have got regular period within 25-27. but my period has not come in my regular time. It has postponeded to 29th day. i was asked to come for hormone injection treatment from 30th day.shall I GO FOR TREATMENT?or i have to ask for the doctor?is it because of this tablet? reply me please.