I am on the pill. i am not pregnant but i havent had my menstrual cycle this month?

Pregnancy test: If you had sex since your last period, do a home pregnancy test. If the result is negative repeat the test 4-5 days later unless you get a period by then. Use first morning urine and follow the instructions for the test carefully. Consult this site. http://www.nichd.nih.gov/health/topics/menstruation/conditioninfo/Pages/causes.aspx Wish you good health!