I have been feeling sick lately, my stomach hurts a lot. I feel constipated and I feel like I have to pee a lot. In the morning and night I feel nauseous. I took two hpt but both were negative. I should have my period next week. I've been cramping the last two days with lower back pain. Along with all that I've had heartburn and my body feels so tired. Do you think I'm pregnanat? How soon can you tell??