Can I be pregnant ?

I was suppose to get my period yesterday but I haven't gotten it . I did experience really bad abdominal pain, headaches, fatigue, fever was low and up, appetite was larger but I did not experience any spotting or nausea ( after I would eat it would feel like I would want to but didn't) I took a pregnancy test on September 1 and came out negative, still been feeling like this. Should I be worried ?