Hi Since your doctor has already started the treatment I presume your basic subfertility workup is normal ( hormone tests and fallopian tube patency test for you and semen analysis for your husband). Injection ovidac contains the hormone human chorionic gonadotrophin. It is given to cause release of ova (egg) from mature ovum. It does not cause delay in the period. The delay could be due to pregnancy. Get a pregnancy test done. Are you taking progesterone like duphaston? Progesterone can cause some delay in periods. Good luck. I hope I have answered to your satisfaction.