Weird signs, need reurance. am I pregnant?

I asked this question earlier but I need reurance. First off, January 16th I got a period like the usual, but this period was weird. It wasn't as heavy as it usually was, it was medium in fact. And on top of that, it only lasted about 2 days, when my normal periods last 4-5 days. Lately I've very, very mood, I have mood swings like no other. I feel extremely tired, I'll sleep for 7 hours and then get tired again in about another 7 hours, I've been getting random headaches on and off, and sometimes random chest discomfort and back/shoulder pain. My calves are also very sore, my feel a little bit tender, not badly though. I feel really foggy and spacey, and sometimes really shaky. My period was due on the 15-16th of February, it's been regular like that for as long as I can remember. I read somewhere that implantation bleeding can be mistake for a period. Also, the last time I had , was December 24th - January 1st. When I went up to see my fianc�e. I'm 17, about 105 pounds, and about 5'2", I've also been very, very stressed lately with family, school and relationships. I've also been randomly nauseated a few times, and had some slight insomnia, worse than usual. All I really want to do is sit around, sleep, and eat, but I only want to eat certain foods that I'm craving. Anything else I just won't eat it. Am I pregnant? Should I get a test now? Or wait?