I've wiped blood but it disappeared and took a pregnancy test but came back negative period hasn't came was due on the 26th . what could be going on ?

Some thoughts...: Pregnancy is the common cause of a missed period. If not pregnant, other causes of a late or missed period include: excessive weight loss or weight gain, increased exercising, emotional stress, having an illness, traveling, medicines (especially birth control pills), hormonal disorders, etc... A repeat pregnancy test can be done 1 week after that first test, and if negative, means not pregnant.