My period was late by many days so I took a pregnancy test and it came out negative. Then days later where at that point my period was two weeks late, my period came but not like it used to. It was all just brown blood and the smallest amount red. Usually I bleed a lot of day one and two but this time it was very light. Usually it lasts like six days but this time it lasted only three. I took another pregnancy test and it came out negative again so what could this mean?