Painful periods at your age are likely to be caused by a high amount of prostaglandins released during ovulation. These cause the uterus to contract. Consult your doctor for instructions regarding how much to take and when. Always take them with food or milk to avoid stomach irritation. An alternative treatment is birth control pills.
Women often get relief from painful menstrual cycles while on the pill.
My period was about 2 or 3 days late this month but came without any signs, breast tenderness, cramping, etc. My flow was lighter at first, then heavier, with minimal pain. If a miscarriage occurs and you are Rh negative, antibodies develop that can prevent you from carrying a future health baby to term. If Rh negative, you will receive medication to prevent these antibodies from forming. There is a limited time period in which you can do this, so call your physician or healthcare provider immediately.