Pregnant?

So I've been feeling weird lately and I thought it was just because I started college 3 weeks ago and everything is different than I'm used to. But my symptoms are like, headaches, nausea at times, but really hungry other times, bloating, some constipation, back pain. And I read online that if you start your period two days early, you could be pregnant (doesn't make any sense, but I'm still concerned) And that's what happened to me. Anybody know if it's true?