my last period is last Jan, 29,and my cycle is 24 days,so my period schedule Feb.,21,but last Feb. 19 i have brown spotting almost 5 days,and a little pain at the right side abdominal cramps,backache and headache...is it possible that i'm pregnant?when i try to test at home it come out negative.is it the home test is not accurate?pls. help am confused