Depo shot....

So it's been about 13 days since I went on birth control. 1st time. I'm on Depo. And according to eve, I'm 7 days late on my period!! Seven days late!!!!! And it's just freaking me tf out! They say every woman is different. Since going on birth control, I've been a MAJOR "b"! My cravings got more weird. I have constant moods swings. I'm always very tired(more than before I started). I get hungry very fast. My appetite changed. .....I've had some of the pregnancy symptoms before I started. But the tests say I'm not pregnant. Is this because I went on birth control or could I be pregnant???