I've been cramping for about 2 weeks straight now. And my period hasn't shown up. Its due the 5th of June. I've also been having tender breast and a little lower back pain. And some pain in my sides. My stomach feels queasy every now and then. And I'm so tired throughout the day, but I can't sleep at night. And I've noticed I'm always hungry. I know its too early to test. But when is the best time and should I be worried.?