What Causes A Delayed Period And Abdominal Pain?

i am a PCOD patient and i am married and have 2 kids and after the kids were born - i got my pcod problem again . latest is that i got my periods on May 9th 2010 and after that i have not got my periods and now i have pain in abdomen area - as if i wil have my periods - but i have not got my periods yet - advice me whether i am pregnant or not - if am pregnant - wat should i do