<s>[INST] Hi DoctorThis is Amla, i have regular periods of 28 days. i am planning for pregnancy. i got a injection on my 7th day from my last period and on 13th day- i had a ovidac 5000 by the doctor.So does this injection delays the regular period of 28 days. today i am on 30th day, cold this be a symptom for pregnancy. [/INST] 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 Vidal 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 phaeton? Progesterone can cause some delay in periods. Good luck. I hope I have answered to your satisfaction. </s>