Pregnant and negative results? 10 points best answer help please?

Ok so i just tested and it came out negative(though i know there are false negatives) so then were did all symptoms came from?i had fatigue, tired and sleepy all the time, waken up at 4:30 am every morning,moody, wanting to cry for no reason, increased hunger, frequent head aches, heart burn twice, nausea off and on, vomited twice,back ache(though i was a level 7 gymnast and had a back injury so I'm not sure were the back pain is from) tender and my bf says they have gotten bigger(though i can't tell so much). We had this week and i spotted brown after that. I don't understand why I'm having pregnancy symptoms that i never had before during my "period" and still getting a negative.