Im 16 and I have this gut feeling im pregnant. My period ended yesterday which usually lasts 7 days. The first day of my period is usally heavy and have bad cramps but I had no cramps and it was light. I feel nauseous, minor headach, feeling exhausted ,some pain between breasts,I always feel hungry even after I ate. I took a pregnanacy test 2 days before expected period at night and it came out negative. Is it possible I could be pregnant ?