All in my head or pregnant?

Hello,

Well my last period was on january 4 or 5 and this month i missed it. I was supposed to get it around the same days since my period is very regular. My stomach has beenvery strange, i have these cramps that feel like menstrual cramps but they havebeen going onfor more than a week already and no period. i have some sharp pains in my lower abdomen and it has been 2 days that i have difficulty sleeping at night. These pains wake me up at night or i am just tossing and turning because my stomach feels very bloaded. I have been into a lot of websites and they all say that my uterus is stretching. I also have been very gassy and hungry. I used to not pee as often as i do now. Since i have been researching a lot, i did a pregnancy due date calculator. I put in the first day of my last period which was the 5th of january. And it said i might be 5 weeks pregnant today.All the symptoms of weeks pregnant are the same ones i am having except for the tender breats. I dont know if this is just in my head because of all the research ive done or could i be pregnant? Can someone that knows please tell me what is going on?

Thanks.