So confused

my cycle only lasted for two days, and that has never happen for before. my cycle is usually long like 7-days days. what made it so bad was that it was very light. my cycle came on a saturday and by monday it was total gone. I am so confused. I have take a test but they came back negative. I have all the signs of bein pregnant. Ex sickness all during the day, i cant stop using the rest room. My attitude is bad for some reason. and i have been having these mild cramps that i normal dont even have. When my cycle is on. Is there any thing that u can tell me or let me no wat goin on? Thanks