Hi,
There's a long list of issues that can cause abdominal cramps without the presence of a menstrual period, for example: a late or irregular period, pregnancy, stress, indigestion or digestive disorders, an illness, or endometriosis, etc...Menstrual cramps are caused by the uterus contracting when it expels it's lining. For many women cramps can happen 3 to 5 days before a period begins, and also during a period.