<s>[INST] i am 41 year old and having 3 children and i was using nurestrate from 2009 to 2013 november and my period was off till today and i want to fall pregnant how long must i wait in order to conceive and is it posseble to fall pregnant even if my period still off? [/INST] HI, Thanks for the query. I understand your concern.  Substrate is an injectable contraceptive. Here menses are stopped/ irregular thus avoiding ovulation & conception. Normally it takes 6-8 months to restart the ovulation, after last injection.  If the menstruation does not resume after this period, you should get gynecologists advise knowing the cause of absent periods (POD? Ovarian or thyroid disorders, pituitary disorder, fibroid uterus, early menopause)& get it treated - have regular menses with ovulation regularly & the try for conception.  Yes, to have normal menses with ovulation is essential for natural conception. But in case you are thinking of test tube baby with abrogation, it need not be there. Please consult a fertility specialist in that case.  Thanks. </s>