PCOS amd pregnancy symptoms ?

I have poly cystic ovarian syndrome and I have also recently started having pregnancy symptoms. My husband and I have been married for over a year and have been wanting children since we got married. So in December of 2010 I was put on metfomin 500mg 3 pills everynight. I had been having periods almost every two weeks for a few months that were very heavy. Well I believe maybe the last 2 months my periods have been very very light. I've had nausea vomiting my have been hurting my are very sore with shooting pains and knave not had a period this month and I've also been cramping ..I took a hpt and it was negitive..not sure what to do and wonder if I am pregnant.