Hello dear! I appreciate sharing your concerns with us on HCM! Delay of your menstruation is more likely to have happened from the urgent contraceptive pill you have used. As known, Postinor or other pills used for this purpose contain high doses of estrogen that make the womb inappropriate for a conception. But the most common side effect of these pills, is menstrual cycle disorders. So delay of menstruation may occur, erlier menstruation or spotting too. You have done the pregnancy test already which has resulted negative, so don t worry. I would recommend you an urine test, since you are prone to urinary infections to see if there is anything wrong with it, and take the proper medication. If you find helpful this answer please kindly click I find helpful this answer and write a review to help us assist you better. I wish you a good health! Take care! DR ERIOL.