I have pregnancy symptoms that I've never had when starting my period. Am I pregnant?

My husband and I are trying to get pregnant. My period is due in 3 days and my lower back hurts, my stomach is queasy at different times during the day, I'm tired, sometimes grouchy, and I have this stabbing pain in my right side just under my rib cage towards my back. Could I really be pregnant? I've never felt like this when my period's about to start. I took a test this morning and it was negative.